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Psychiatric diagnostic concepts among German-speaking psychiatrists
Psychiatric Diagnostic German-speaking
Concepts Among Psychiatrists
John E. Overall and Hanns Hippius
T
HIS ARTICLE is concerned with an investigation of the nature of diagnostic concepts employed by psychiatrists in Germany, Austria, and Switzerland. The study was designed to evaluate the validity of a standard rating scale for description of differences among the German diagnostic classes, to provide prototype profiles that should facilitate understanding of the German nomenclature by English-speaking psychiatrists, and to study relationships between diagnostic concepts held by German-speaking and American psychiatrists. In each modern country a collection of diagnostic concepts has developed or has been adopted to span the range of psychopathology recognized by psychiatrists in that country. Diagnostic labels are abbreviated designations for complex patterns of psychopathology. Associated with each different diagnostic classification is the conception of a typical patient, or, as we shall call it, a diagnostic stereotype. By studying the diagnostic concepts, or stereotypes, held by psychiatrists in a particular region of the world, one can gain insight into the nature of psychopathology as it is recognized in that cultural setting. Thus the present study of diagnostic stereotypes held by German-speaking psychiatrists should provide a meaningful description of types of psychiatric disorders that are recognized in the academic and cultural context of German-speaking Central Europe. The translation of abstract and complex diagnostic nomenclature from one language to another poses a difficult problem. In this research we have approached the problem by reducing such complex concepts to more basic, simple, symptomdescriptive terminology. The symptom and behavior constructs of the Brief Psychiatric Rating Scale (BPRS) were chosen to provide a standard descriptive vocabulary subject to precise translation for use by psychiatrists in different countries.’ Most of the rating constructs in the BPRS involve nontechnical terms that exist in the everyday language of any western country. The few more technically psychiatric terms, such as hallucinatory behavior and blunted affect, have such universally recognized significance among professionally trained individuals that we believe good translation to be possible. Even these more specialized terms are also elaborated in the everyday vernacular in the rating scale itself. In short, the validity of the approach that we have taken to the problem of comparing diagnostic concepts held by psychiatrists in different countries rests on reduction of the complex diagnostic concepts to simple symptom-descriptive terms and the accurate translation of those basic terms. We believe that we have accomplished this task adequately to provide for meaningful examination of diagnostic concepts held by
From the University of Texas Medical Branch, Galveston, Tex., and Universitiit Miinchen, Germany. John E. Overall, Ph.D.: Professor, Universiiy of Texas Medical Branch, Galveston, Texas. Hams Hippius, M.D.: Professor and Dire&or. Psychiatrische Klinik und Poliklinik der Universitiit Miinchen. Germany. @ I974 by Grune & Stratton, Inc. Comprehensive Psychiatry. Vol. 15, No. 2 (March/April). 1974
103
104
OVERALL
AND
HIPPIUS
German-speaking psychiatrists and comparisons between the German and American nomenclatures. The study described in this article was patterned after similar studies previously done in the United States, France, Czechoslovakia, and Italy. The same standard symptom-descriptive terminology was used in all studies to facilitate comparisons of diagnostic nomenclatures. In the United States, Overall and associates2-4 conducted investigations using the BPRS’ to characterize similarities and differences among diagnostic stereotypes represented in the APA standard nomenclature.” Thirteen functional psychotic types were found to cluster into four major groups: schizophrenias, depressions, manias, and paranoid syndromes. While there was some suggestion of differentiation within the schizophrenia cluster, the phenomenological differences between the four major profile groups were much greater than differences within the groups. In France, Pichot and associate@’ completed a study of French diagnostic stereotypes using a careful translation of the BPRS. The study was perhaps particularly important in France because at that time there was no official standard nomenclature. Consistency among French psychiatrists in the conceptions of 12 diagnostic types was demonstrated. From the point of view of American psychiatry, the study was important because it made evident certain differences in meaning for apparently similar diagnostic terminology. Diagnostic labels in French that sound like familiar American labels have in fact quite different meanings. In addition, the results from the study emphasized the uniqueness of the hallucinatory psychosis, for which there is no counterpart in the American nomenclature. A similar study was undertaken in Czechoslovakia by Engelsmann and associates8 using a Czechoslovak translation of the BPRS. In this study the World Health Organization international classification was examined. Perhaps largely due to the standard diagnostic concepts considered, the relationships between results obtained in this study and those obtained from the study completed in the United States were quite good. The Czechoslovak study has perhaps its primary importance in providing quantitative rating-scale definitions of the WHO international classification concepts. An identically designed study undertaken in Italy has recently been completed.9 The results again revealed four major types of psychiatric disorders represented among the 12 Italian diagnostic concepts that were considered. In view of the series of similar studies completed in different countries, it seemed important to examine in the same manner diagnostic concepts held by Germanspeaking psychiatrists. The BPRS was translated into German for use in describing the symptom and behavior characteristics of 12 diagnostic types. The 12 types were selected on the basis of general familiarity and frequent use, with consideration being given to spanning the full range of major psychopathology. The purposes of the study were to evaluate the adequacy of the BPRS for characterizing differences among German diagnostic classes, to provide symptom-descriptive profiles representing the major German diagnostic classes, and to examine relationships between the German and American psychiatric concepts as they are represented in BPRS symptom rating profiles.
DIAGNOSTIC
105
CONCEPTS
METHOD A total of 108 German-speaking psychiatrists from Germany, Austria, and Switzerland participated as expert judges in this study. Of the total group of experts, 90 were employed in university hospitals and I8 in the Department of Psychiatry of the Max-Planck-lnstitut, which is somewhat similar to the American NIMH. All were experienced clinicians familiar with the diagnostic nomenclature with which the investigation was concerned. Each psychiatrist was provided with I2 rating forms. At the top of each form was typed the name of a psychiatric diagnostic class. The judge was asked to conceive of a typical patient of the type named at the top of the form and to provide a quantitative symptom profile to describe that type of patient by indicating level of severity for each of the I6 symptom rating constructs. Multivariate analyses were undertaken to examine similarities and differences between the diagnostic profiles and to investigate the extent of agreement among psychiatrists in the nature of symptom profiles that they provided to portray various diagnostic groups. Multiple discriminant analysis and Mahalanobis DZ statistics were employed for this purpose. A mean prototype profile was computed to describe each diagnostic type. A distance function classification procedure was used to assess similarities of individual BPRS profiles to the 12 diagnostic prototypes. The stereotype profiles provided by different psychiatrists were analyzed using this program to determine the degree of consensus within diagnostic class and the extent of recognizable distinction between profiles that were supposed to represent different diagnostic classes. Following the analyses of consistencies of the diagnostic stereotypes held by different psychiatrists and the subsequent definition of prototype profiles representing I2 German diagnostic classes, multivariate analyses of relationships between German and American diagnostic concepts were undertaken. A matrix of O* distance function coefficients was computed, and an empirical cluster analysis was employed to classify the combined German-American diagnostic prototypes according to similarities and differences in profile patterns. The purpose of this analysis was to determine whether each major phenomenological type is represented in both German and American diagnostic classifications. Finally, a Q-type factor analysis of profile pattern correlations was undertaken in an effort to identify a basic set of profile patterns that should be adequate to represent the major phenomenological distinctions that are common to both the German and American nomenclatures, Not all diagnostic distinctions are based on symptom and behavior characteristics. It was considered worthwhile to determine how many and what types of symptom and behavior patterns are highly distinguishable in the diagnostic conceptions of the different countries. Even though diagnostic classification systems may not correspond perfectly, it is still possible that the same basic phenomenological subtypes exist in the clinical populations. Identification of the basic phenomenological distinctions that are common to diagnostic nomenclatures of different countries should provide some indication of the nature of underlying disorders that appear in substantially similar form across national and cultural boundaries.
RESULTS
Multiple discriminant analysis is a method for studying the configural relationships among several diagnostic groups in a reduced discriminant function space. The primary implication of the analysis in this instance was determination of the number of significant dimensions of symptom profile difference separating the 12 diagnostic stereotypes in the minds of German-speaking psychiatrists. The number of significant discriminant dimensions provides information concerning the minimum number of discriminably different symptom profile patterns represented among the 12 diagnostic groups. One dimension is required to describe differences between two groups, two dimensions may be required to account for differences between three groups, three dimensions may be required to account for differences between four groups, and so on. Several groups can differ along a single continuum; however, if an analysis reveals that k dimensions are required to represent all significant group differences, then there must be at least k + 1 discriminably different groups.
OVERALL
106
AND
HIPPIUS
In the analysis of diagnostic profiles provided by German-speaking psychiatrists, the maximum number of discriminant dimensions would be 11 if each of the 12 types were to differ significantly from the others. The 11 roots of the determinantal equation ) B - XW ( = 0 were 4627, 2644, 2223, 1168, 763, 292, 106, 74, 50, 30, and 10, so that the trace or sum of roots was 11987. The sum of all roots is approximately distributed as a chi-square statistic with p(k-I) degrees of freedom, where p = 16 symptom measurement variables and k = 12 groups.‘O The x2 = 11987 with 176 df is recognized to be highly significant. This overall test supported the conclusion that among the 12 diagnostic types are at least some types that psychiatrists consistently conceive as different from the others in terms of BPRS symptom profile patterns. As described by Overall and Klett,‘O a strategy for determining the number of significant discriminant dimensions involves testing the significance of the sum of all possible roots, then subtracting out the first root and testing the significance of the residual to determine whether any other dimensions of group difference need be considered, then subtracting out the second root and repeating the test, and so on until the residual is not significant. At any stage, a significant x2 test is interpreted to mean that at least one more dimension of group difference is significant and has not adequately been represented in the previously defined discriminant functions. Each additional significant discriminant function suggests the presence of at least one additional diagnostic group that can be distinguished from the others in terms of BPRS symptom rating profiles.
Sum of all roots less X, less X, less X, less h, less h5 less X, less h, less X, less X, less h,,
X2
df
P
11987 7360 4716 2493 1325 562 270 164 90 40 10
176 150 126 104 84 66 50 36 24 14 6
0:oo 1 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 N.S.
The series of x2 tests performed on residual variances remaining after partialling out successive roots of the determinantal equation yielded consistently significant results until after the tenth root was subtracted out. The x2 = 40 with 14 df obtained after partialling out the first nine roots suggests that a tenth dimension is required to account for all discriminable differences among the 12 diagnostic types. The x2 = 10 with 6 df fails to support the existence of an eleventh significant dimension. These results suggest that at least 11 of the 12 diagnostic concepts were consistently attributed different BPRS profile patterns by the expert judges. Mean BPRS profiles for the 12 diagnostic types computed from the rating profiles provided by the several psychiatrists are presented in Table 1. These mean profiles will be accepted as prototypes of patients who are considered typical of the 12 diagnostic classes. Although it is possible to gain some insight into the particular
simplex
3.3
4.8
Endoreaktive
Mischpsychose
1.3
Manie
Dysthymie
5.2
2.9
3.0
2.7
Endogene Depression
Persijnlichkeitswandel
Schizophrener
Schizophrenic
Hebephrene
Schizophrenia
6.0
CoenPsthetische
Schizophrenic
2.4
3.0
3.1
2.4
Paranoia
Schizophrenic
peranoid-
peranoide
katatone
halluzinatorische
Schubfiirmige
Schizophrenic
Schubformige
Schizophrenic
Schubfiirmige
4.3
5.0
1.2
6.1
2.6
2.8
2.7
4.7
3.7
4.5
4.6
3.9
3.5
2.7
1.4
3.7
5.4
5.3
4.7
4.0
2.7
4.0
4.0
6.0
3.2
1.2
3.3
1.3
4.2
3.6
4.8
3.0
1 .6
4.6
3.7
5.2
3.4
3.6
1 .l
6.0
1.6
1.9
1.7
2.0
1.6
2.1
2.1
2.0
Table 1. Meen BPRS Symptom
4.0
2.8
4.7
2.8
2.3
2.5
3.2
3.3
3.2
4.6
4.3
6.0
2.6
1.3
2.3
1.3
4.2
3.2
4.6
2.5
1.9
3.2
2.8
5.5
2.3
1.1
6.0
1.0
2.1
1.8
2.8
1.5
3.1
3.6
3.3
2.6
Profiles for 12 German
4.0
5.0
1 .l
6.4
2.2
2.6
2.2
3.1
1.9
1.9
2.0
2.0
3.1
i .9
3.0
1.3
3.0
2.6
3.0
2.5
4.9
4.5
4.6
3.7
Diagnostic
3.9
I .a
1.9
1.9
3.5
2.8
2.8
3.3
6.1
5.8
6.1
3.8
Types
3.0
I .o
1.2
1.3
2.5
1.9
2.8
4.4
1.4
6.1
2.8
4.2
2.9
4.1
1.0
5.9
4.6
4.8
4.0
3.1
1.5
2.0
2.0
4.0
2.9
2.1
3.0
2.1
3.6
3.6
3.9
2.8
3.1
3.8
3.4
5.1
3.4
1.4
2.0
2.4
4.0
3.3
4.3
4.8
4.2
5.6
5.2
4.6
2.6
2.1
1.3
2.6
5.9
5.3
5.3
3.6
1.9
2.8
2.9
3.2
2
5
0’
8
0
Y
z
z
E
OVERALL AND
108
HIPPIUS
groups that are most distinguishable by examining mean scores on the various discriminant continua, the substantial number of significant discriminant functions identified in this analysis lessens the utility of that approach. In view of the number of significant group differences, a more meaningful question concerns which particular diagnostic concepts are not discriminably different in terms of associated BPRS profiles. To answer this question, a matrix of Mahalanobis D2 coefficients was calculated to provide an index of difference between each pair of diagnostic groups. The D2 statistic can be converted to an F ratio to provide a test of the significance of the difference between multivariate group means relative to the variability of profiles provided by different psychiatrists.l” For the degrees of freedom that are available, the minimum value of D2 that should be taken as evidence of consistent differences in the psychiatrists’ stereotypes of two diagnostic classes is approximately D2 > 0.75. The matrix of D* coefficients relating all pairs of the 12 diagnostic groups is presented in Table 2. From examination of the Dz coefficients, one is led to conclude that the expert judges attributed a distinct BPRS profile pattern to each diagnostic class with enough consistency to result in statistical significance. Statistical significance in this study of diagnostic stereotype profiles is an indication that the differences between the main profiles are substantially large relative to the variability of profiles provided by different judges. The results are accepted as confirming that the BPRS symptom rating constructs provide an adequate vocabulary for describing differences among stereotypes of diagnostic classification as conceived by German-speaking psychiatrists. Apart from the question of statistical significance, one can gain insight into the relative similarities and differences among diagnostic concepts by examining the D2 coefficients. It is apparent that groups 7 and 8 tended to be least discriminable in Table 2. D2 Distances Between 1.
-
15.8
2.
15.8
3.
13.3
Diagnostic
Prototype
Profiles
12.3
12.4
43.7
31.5
31.4
15.7
8.9 14.0
13.8
12.8
40.6
29.5
26.8
8.9
17.1
13.6
16.2
20.3
17.5
51.6
35.2
37.0
12.5
13.3
28.2
20.4
-
7.3
4.2
7.3
-
13.4
4. 28.2
4.2
17.1
-
24.2
22.3
20.0
19.8
42.7
28.2
26.5
13.1
5. 20.4
15.7
13.6
24.2
-
14.5
13.3
14.6
30.5
41.6
18.2
11.1 9.8
6.
8.9
14.0
16.2
22.3
14.5
-
3.0
2.0
35.3
24.0
22.8
7.
12.3
13.8
20.3
20.0
13.3
3.0
-
1.4
24.9
28.9
15.2
8.1
8.
12.4
12.8
17.5
19.8
14.6
2.0
1.4
-
34.7
33.0
23.6
11.2
9. 43.7
6.2
16.9 24.4
34.0
34.0 _
24.4
8.7
40.6
51.6
42.7
30.5
35.3
24.9
34.7
-
56.0
10.
31.5
29.5
35.2
28.2
41.6
24.0
28.9
33.0
56.0
-
11.
31.4
26.8
37.0
26.5
18.2
22.8
15.2
23.6
6.2
12.
13.4
8.9
12.5
13.1
11.1
9.8
8.1
11.2
16.9
1 = Schubformige 2 = Schubformige
katatone Schizophrenic. paranoide Schizophrenic.
3 = Schubformige
paranoid-halluzinatorische
4 = Paranoia. 5 = Coenasthetische 6 = Hebephrene
Schizophrenic.
Schizophrenic.
7 = Schizophrenia
simplex.
8 = Schizophrener
Personlichkeitswandel.
9 = Endogene 10 = Manie.
Depression.
11 = Endoreaktive 12 = Mischpsychose.
Dysthymie.
Schizophrenic.
8.7 -
DIAGNOSTIC
CONCEPTS
109
terms of BPRS symptom profiles, and the fact is that simple schizophrenia and schizophrenic personality are not easily distinguishable in anybody’s conception. Groups 9 and 10 (depression and mania) are the most discriminable, and groups 9 and 3 (depression and paranoid-hallucinatory schizophrenia) are next most discriminable. From this type of casual inspection, we recognize three major discriminable types-depressive, manic, and schizophrenic. An empirical profile cluster analysis was used to classify the diagnostic patterns into syndromes or major phenomenological classes on the basis of similarities and differences represented by the D2 coefficients. The computer analysis revealed relatively homogeneous clusters of diagnostic types that differed substantially from one another. Although the patterns that were classified into each cluster differed to a statistically significant extent, the differences within clusters tend to be small relative to the differences between clusters. Four major phenomenological distinctions represented in the diagnostic concepts of German-speaking psychiatrists were found to be the following: Core Schizophrenias
Hebephrene Schizophrenic Schizophrenia simplex Schizophrener PersGnlichkeitswandel Paranoid Syndromes
Schubfiirmige paranoide Schizophrenic Paranoia Depressive Syndromes
Endogene Depression Endoreaktive Dysthymie Mania
Manie The distinctness of these four profile patterns can be appreciated by inspection of the prototype profiles in Table 1, and the cluster grouping can be verified by examination of the Dz coefficients in Table 2. Diagnostic profiles that were not included in one of the four distinct categories by the computer analysis can be seen to fall between the identified clusters. The similarities of the four major phenomenological classes to those identified among American, French, Czechoslovak, and Italian diagnostic stereotypes should be noted. The diagnostic concepts of German-speaking psychiatrists appear to span the same major domains of psychopathology that are represented in diagnostic concepts of psychiatrists in other countries. The cluster grouping suggests that most of the differences between diagnostic concepts of the German-speaking psychiatrists should be susceptible to representation in .a simple three-dimensional model. This is suggested because a maximum of three dimensions is required to represent the multivariate profile differences among any four groups. Referring back to the multiple discriminant analysis that was undertaken as the initial analysis of these data, it can be verified that 79% of the total discriminable variance among the 12 diagnostic groups was accounted for by the first three discriminant functions. Recognizing the uniqueness of the manic profile pattern, the manic group can be left out to reduce the required
110
OVERALL
AND
HIPPIUS
dimensions for an adequate discriminant function model to two. Although additional dimensions are statistically significant, most of the differences between schizophrenic, paranoid, and depressive syndromes can be represented in only two dimensions. A simple two-dimensional model should provide a convenient representation of relationships among the diagnostic concepts in the BPRS symptom profile context. A second multiple discriminant analysis was accomplished with the manic group omitted for the purpose of developing a geometric model to represent relationships among the remaining 11 diagnostic concepts in a two-dimensional space. The results are shown in Fig. 1, where the grouping previously derived from cluster analysis of D2 coefficients is clearly verified. In the geometric model, distances between points represent the magnitudes of overall profile differences. Symptom vectors have been inserted into the discriminant function space to provide an indication of the unique symptom characteristics associated with each region. The computer program used for the analysis and the method of positioning symptom vectors in the discriminant function model have been presented by Overall and Klett.‘O The first discriminant function separated the depressive profile patterns from all others in the BPRS measurement space. It is represented by the vertical axis in Fig. 1. The second discriminant function, represented by the horizontal axis, separated the core schizophrenic patterns from the paranoid patterns. Even in the reduced two-dimensional projection, the three major diagnostic types appear
4 3
SUSPICIOUSNESS
4 .
\
-’ UNUSL 2 THOlJ( . 1 HOSTILITI
HALLUCINATORY
f
p&PT ”
!
WITHDRAWAL
\
DEPRES MOOD
RETARDATION
Fig. 1. Conffgural relationships among 11 diagnostic stereotypes with vectors indicating target symptoms in various groups: (1) schubfiirmige katatone Schizophrenic, (2) rchubfiirmige paranoide Schizophrenic, (3) schubf6rmige paranoidhalluzinatorische Schizophrenic, (4) Paranoia, (6) coeniisthetische Schirophrenie, (6) hebephrene Schizophrenia, (7) Schizophrenia simplex, (8) schizophrener Persiinlichkeitswandel, (9) endogene Depression, (101 endoreaktive Dysthymie, (11) Mischpsychose.
DIAGNOSTIC
111
CONCEPTS
phenomenologically distinct. As indicated by the symptom vectors that were inserted into the discriminant function model, BPRS symptoms of anxiety, guilt feelings, and depressive mood tended to be present at relatively high levels in the depressive profile patterns. Hostility, suspiciousness, and unusual thought content marked the paranoid profile patterns. Conceptual disorganization, mannerisms and posturing, blunted affect, and emotional withdrawal were relatively more prominent in the core schizophrenic patterns. These phenomenological distinctions can readily be verified by reference to the mean profiles that were presented in Table 1. As a method of examining in greater detail the discriminability of rating profiles provided by the expert judges to represent the 12 diagnostic types, a computer diagnostic classification program was used. lo The program calculates an estimate of the probability with which any particular BPRS profile belongs in each of the several specified populations, and the profile is then assigned to the diagnostic category in which it is judged to have the highest probability of occurrence. In this application of the method, the diagnostic populations were specified to have means equal to the mean profiles shown in Table 1. In effect, the program determined whether each individual profile was more like the mean for the diagnostic group that it was said to represent or more like the mean for some other diagnostic group. If all 108 psychiatrists had been perfectly consistent in recognizing symptom and behavior differences among the diagnostic classes, there would be no overlap in the distributions and the computer program should be able to correctly assign all profiles. Where the computer assigned a profile to the wrong diagnostic class, it was because the profile was more like the pattern designated by a majority of the judges to represent the alternative diagnostic class. Thus the diagnostic classification program provided a method of examining consistencies among the psychiatrists’ conceptions of the diagnostic profile patterns, as well as the discriminability among the different types. Results from computer assignment of the individual profile patterns among the 12 diagnostic groups are presented in Table 3. In each row of the table are tallied profiles that were designated by the expert judges to represent one particular diagnostic type.3 The successive entries across each row indicate the computer assignment. For example, in the fourth row from the top are entered results from Table 3. Computer
Classification
of German
Diagnostic
Stereotype
Profiles
computer
r ._ ;
9.
12.
0
2
9
2
4
0
0
0
0
51
17
25
2
l
1
0
0
0
1
9 2
3.
4
10.
11.
8
4.0
7.
8.
1 1
4.
6.
2.
2.
3.
5.
1. 1.79
3
91
1
2
1
0
0
0
0
87
3
1
3
0
0
0 0
0
11
0
2
1
6
0
67
0
4
l
o
0
5
2
.m r :
5.
0
6.
12
2
0
0
0
52
14
20
0
2
3
3
z
7.
1
0
1
1
2
13
42
28
0
0
0
13
2 0
l 0
1 0
2 0
20 0
25 0
56 0
0 95
0
0
1
0
13
0
0
0
8.0 9.0
0
0
1
0
0
0
0
0
11.
0
0
0
0
1
0
0
0
18
105 0
68
5
12.
8
0
3
2
3
1
3
0
1
5
15
54
10.0
112
OVERALL
AND
HIPPIUS
computer classification of profiles that were offered by the psychiatrists to represent paranoia. The computer recognized 87 of them to be most like the group norm or prototype for paranoia. Eleven were found by the computer to be more like the prototype for paranoid schizophrenia, a reasonable confusion, and only nine of the reputed paranoia profiles were assigned by the computer to one of the nonparanoid categories. Entries in other rows of the table can be evaluated in a similar fashion. Examination of the computer assignments of individual profiles provides another approach to understanding the relative similarities and differences in conceptual stereotypes of psychiatric disorders. The computer does not actually make mistakes in evaluating similarities of profiles. When the computer misclassifies a profile, it is because the profile provided by a particular expert to represent his conception of a given diagnostic type is more like that which the majority of experts specified for another type. The entries in Table 3 reveal that most diagnostic categories were clearly discriminable. Some degree of confusion between types 2, 3, and 4 is apparent. Types 6, 7, and 8 form another cluster within which distinctions are not highly apparent. Finally, some overlap between types 9 and 11 is evident. The catch-all Mischpsychose tends to be least distinct from all other groups. These conclusions are supported by the proximities of the several diagnostic groups in Fig. 1 and by the D2 coefficients in Table 2. Having verified that the BPRS is adequate for description of differences in conceptual stereotypes of diagnostic classification among German-speaking psychiatrists and having evidence of considerable agreement among the psychiatrists concerning the distinctive features of each type, analyses were next undertaken -to evaluate relationships between diagnostic concepts of German-speaking and American psychiatrists. Prototype profiles representing 13 diagnostic types described in the standard American Psychiatric Association nomenclature have been presented previously.3 A matrix of D2 (distance function) coefficients was computed to represent relationships between the German and American diagnostic profiles. For these calculations, the variability within profile groups was disregarded and the squared distance between each pair of diagnostic prototypes was calculated as the sum of squares of differences in mean scores on the 16 BPRS symptom rating variablese4 The 12 x 13 matrix of D2 coefficients relating each German diagnostic concept to each of the American diagnostic concepts is presented in Table 4. For each of the diagnostic concepts of German-speaking psychiatrists, one can identify the nearest equivalent diagnostic concepts in the American nomenclature. It is readily apparent that the paranoid-type profiles in the German-speaking psychiatrists’ conceptions are most like the paranoid types as conceived by the American psychiatrists. The core schizophrenic types in the German system are represented by profiles that are most similar to those in the core schizophrenic cluster within the American system. The depressive and manic patterns are obviously similar within the two diagnostic schemes. Although the same general patterns are present in similar form within the diagnostic conceptions of Germanspeaking and American psychiatrists, it does not appear feasible to establish a one-to-one correspondence between specific diagnostic classes on the basis of BPRS profile patterns alone. Such an attempt would lead to apparent discrep-
DIAGNOSTIC
113
CONCEPTS
Table 4. 1.
2.
3.
German
Diagnostic
Prototypes
4.
5.
6.
7.
8.
9.
10.
11.
12.
0
1. 116.6
45.4
78.5
14.5
85.2
84.4
82.0
89.2
157.8
29.5
93.8
59.1
g
2.
80.4
23.2
47.1
7.6
56.4
61.1
62.3
68.9
127.4
28.1
73.7
32.8
6
3.
55.4
10.9
la.3
14.6
42.6
48.8
59.9
57.7
143.3
44.5
96.4
32.3
5 o.
4.
27.0
13.4
15.5
33.1
17.5
24.5
34.5
34.9
94.0
56.6
64.0
11.6
5.
12.4
47.1
45.0
77.0
48.1
10.4
20.8
14.8
118.9
95.4
100.9
41.0
,; g
6.
34.6
48.1
41.1
74.8
47.3
16.3
35.8
25.1
161.2
74.2
112.1
51.4
62.0
66.0
48.4
2 .E
a. 7.
82.0 86.4
55.5 68.2
92.8 81.2
61.2 38.3
46.9 55.4
44.7 33.4
33.8 22.4
45.0 30.0
112.0 93.5
41.7
44.6
33.2
9.
39.4
27.0
36.8
36.8
24.7
12.1
15.1
14.8
101.0
49.6
64.6
21.1
g
10.
51.9
24.5
38.8
27.4
24.1
36.8
36.3
46.0
61 .4
42.4
33.4
5.1
.g 11. f 12.
75.1 94.9
59.8 78.3
82.1 107.0
67.8 80.0
32.1
60.0
45.0
62.7
18.0
105.0
15.8
16.5
8.1
118.0
10.7
26.3
a
97.2
69.3
88.7
51.4
195.0
4.3
122.0
73.4
13.
44.5 111.5
75.0
51.7
74.1
78.3
92.9
98.7
ancies that in the opinion of the present writers are due more to sampling variability than to true differences in diagnostic concepts. For example, the American “catatonic schizophrenia” profile is most similar to the German “hebephrenic schizophrenia” profile, although the German “catatonic schizophrenia” profile runs a close second. And from the point of view of the American nomenclature, the German “catatonic schizophrenia” pattern is much more similar to the American “catatonic” pattern than it is to any other. Thus, in spite of the fact that one would encounter difficulties in establishing a one-to-one equivalence between specific diagnostic types on the basis of BPRS profile patterns alone, the Dz coefficients do reveal a highly satisfactory correspondence of specific diagnostic concepts between the German-speaking and American psychiatrists. Factor Analysis of Relationships Among German and American Diagnostic Prototypes
Recognizing certain difficulties in the attempt to establish a meaningful one-toone equivalence for specific diagnostic concepts, it is perhaps more meaningful to ask what broader phenomenological distinctions tend to be represented in both the German and American nomenclatures. If it is assumed that the several diagnostic prototypes from both classification systems can be reduced to a relatively few basic patterns, what should those basic patterns be? Factor analysis can be used to study similarities among profile patterns in much the same way that it is used to study relationships among measurement variables. The product-moment correlation between two multivariate profiles provides an index of the similarity of the profile patterns, with elevation and variability differences eliminated.5 The factors derived from analysis of a matrix of such profile correlations can be conceived to represent hypothetical pure types to which the observed profile patterns relate in varying degree. The matrix of factor loadings resulting from an analysis of (Q-type) profile correlations contains indices of similarity between the observed profiles and the underlying pure types. The analysis can thus result in an understanding of the number and nature of basic profile patterns represented among the larger set of prototype profiles. The 12 diagnostic prototypes from German-speaking psychiatrists and 13 pre-
114
OVERALL
AND
HIPPIUS
viously published diagnostic prototypes from American psychiatrists were intercorrelated to yield a 25 x 25 Q-type correlation matrix. The Q-type correlations were first subjected to an orthogonal powered vector factor analysis,‘O and from the results a marker profile was chosen to represent each distinct factor. The marker profiles selected were the diagnostic prototypes with largest projection on each orthogonal factor. The marker profiles were then used to initiate a marker variable analysis, which stabilizes on an oblique simple structure in which each primary factor is the principal axis of a cluster of profiles that relate empirically to the marker profiles.” A total of six factors were defined in the preliminary orthogonal factor analysis. This was interpreted to mean that the diagnostic prototypes from the two countries include at least six higher order syndromes that are represented by two or more diagnostic prototypes with relatively similar profile patterns. Interest in the analysis was in determining whether each cluster of similar profiles included representatives from both German and American diagnostic schemes. The prototype profile having the greatest relationship to each of the six factors was selected as a marker for one of the distinct underlying patterns. As it happened, the six marker profiles chosen in this manner were all from among the American prototypes. They were as follows, in the order of selection: 1. Schizophrenic reaction, simple type 2. Paranoid state 3. Psychotic depressive reaction 4. Manic-depressive, manic type 5. Schizophrenic reaction, catatonic 6. Schizophrenic reaction, hebephrenic It will be noted that the first four marker profiles clearly represent the core schizophrenic, paranoid, depressive, and manic clusters previously identified. The last two marker profiles suggest that the (American) catatonic and hebephrenic patterns deviate in a consistent manner from the core schizophrenic type across the combined sets of prototypes, resulting in two additional specific types. Using the six profiles indicated above as markers, a Q-type marker variable factor analysis was accomplished to provide indices of relationships of the 25 prototype profiles to six underlying pure type patterns for which the six marker profiles were tentative approximations. The oblique reference structure presented in Table 5 indicates the degree of relationship of the prototype profiles to each pure type. In the Q-type factor solution, Factor I is associated with the core schizophrenic pattern. It is represented in three obviously similar prototype profiles from each diagnostic scheme. It should be noted that the core schizophrenic pattern tends to be represented in the more endogenous, chronic, and less floridly psychotic diagnostic groups. Factor II is associated with paranoid type profile patterns. This distinct configuration appears in three of the American prototypes and two of the German prototypes. Factor III, identified with the depressive profile pattern, is represented in three of the American prototypes and three of the German prototypes. Factor IV is identified with the manic profile pattern, and it is represented once in each collection of diagnostic prototypes. Factor V is associated with acute, active, florid psychosis, as distinct from the core schizophrenic types. Finally, Factor VI is identified with the catatonic profile pattern that appears in sub-
DIAGNOSTIC
Table 5.
115
CONCEPTS
Reference
Structure
Derived from O-Type American
Diagnostic
Factor Analysis of Combined
German
and
Prototvpas I.
II.
III.
Paranoia
.06
e
-.08
Paranoid state
.oo
&I
IV.
v.
VI.
American
Schizophrenic
reaction,
paranoid
Schizophrenic
reaction,
acute undifferentiated
Schizophrenic
reaction,
catatonic
Schizophrenic
reaction,
hebephrenic
Schizophrenic
reaction,
simple
Schizophrenic
reaction,
chronic
Schizophrenic
reaction.
residual
Schizophrenic
reaction,
schizoaffective
- .02
type
-.Ol
-.I4
-.02
.04
.24
-.02
-.I2
.25
-.25
-.30
.73
-.06
_73
undifferentiated
.48
.09
_52 -.06
- .03
-.05
.04
.23
-.ll
.I6
29
-.15
-.08
.02 .63 .Ol
.07
.44
.oo
02
-.07
.28
-.25
.13
.20
.Ol
.35
-.I3
.67
.36
.49
-.I3
Psychotic depressive reaction
.Ol
-.07
.77
depressive type
.Ol
-.02
.71
Manic-depressive,
manic type
.04
-.08
.04
.oo
Manic-depressive,
- .oo
-.I6
.I3
-.15
.08 -.04
.06
-.Ol
Z
.04
-.14
.09
.03 -94 _61
.Ol
.05
.15
.08
.63
.lO
.ll .I3
German Schubformige
katatone
Schubformige
paranoide
Schizophrenic
Schubformige
paranoid-halluzinatorische
- .04 .02
Schizophrenic
Schizophrenic Paranoia Coenasthetische
Schizophrenic
.02
.I2
sr,
.lO
-.29
.28
-.07
.85
.I4
-.06
-.05 -.12
2
.02
-.19
-.21
.22
-.19
.58
-.21
-.03
.14
-30
.14
-.I6
-.20
-.ll
-.I5
-.05
-.Ol
-.05
-.I3
-.09
.12
-.12
simplex
_67
06
Schizophrener
Personlichkeitswandel
_61
99
.05
-.06
.58
.oo
-64
ol
.06
-.Ol
_62
-Z5
_ss
-.02
Endogene
Schizophrenic
Depression
Manie Endoreaktive
Dysthymie
-.13
Mischpsychose
-.09
-.09
.55
Schizophrenia
Hebephrene
.12 -.12
.24
.I3 -.23
.70
.I8
.12
.lO
stantially similar form in the diagnostic conceptions of both German-speaking and American psychiatrists. It should be noted that the American hebephrenic pattern, whieh served as marker profile in the definition of factor V, did not remain the most prominent example of the florid psychotic type in the final rotated marker variable solution. The Aorid psychotic prototype is more similar to the American acute undifferentiated profile. The factor analysis of profile pattern relationships led to recognition of the following major syndrome equivalencies: German
American
Core Schizophrenic Syndromes Schizophrenic reaction, simple Schizophrenic reaction, chronic undifferentiated Schizophrener Persiinlichkeitswandel Schizophrenic reaction, residual
Hebephrene Schizophrenic Schizophrenia simplex
Paranoid Syndromes
Schubfijrmige paranoide Schizophrenic Paranoia
Paranoia Paranoid state Schizophrenic reaction, paranoid
OVERALL
116
AND
HIPPIUS
Depressive Syndromes
Schizophrenic reaction, schizoaffective Psychotic depressive reaction Manic-depressive, depressed
Mischpsychose Endoreaktive Dysthymie Endogene Depression
Manic Syndromes
Manic-depressive,
Manie
manic
Florid Schizophrenic Syndromes
SchubfGrmige paranoide Schizophrenic Halluzinatorische Schizophrenic Coen%thetische Schizophrenic
Schizophrenic reaction, acute undifferentiated Schizophrenic reaction, hebephrenic Schizophrenic reaction, schizoaffective
Catatonic Syndromes
Schubfijrmige katatone Schizophrenic
Schizophrenic reaction, catatonic
The results from the Q-type factor analysis of the combined German and American diagnostic prototype profiles revealed six distinct types of profile patterns, rather than the four previously noted in analyses of the separate sets of data. This came about because similarities in patterns across the two systems produced additional distinct clusters that could not be recognized as such in either set alone. Specifically, the schizophrenic subtypes were found to include three distinct profile patterns across both diagnostic systems: core schizophrenic, florid schizophrenic, and catatonic patterns. In addition, of course, there is the paranoid syndrome that includes paranoid schizophrenia. Thus separate and distinct profile patterns that are quite comparably conceived by both German-speaking and American psychiatrists include manic, depressed, paranoid, core schizophrenic, florid schizophrenic, and catatonic schizophrenic patterns. The catatonic pattern, while distinct enough to form a separate cluster, can be observed to be closest to the florid schizophrenic category. In view of the rather specific nature of the distinguishing features, we would prefer not to emphasize the catatonic pattern as a distinct major phenomenological subtype, although there is an empirical basis for doing so. Prototype BPRS profiles representing the remaining five major types of psychiatric disorders, as derived from the combined German and American diagnostic stereotype data, are presented in Table 6. These major diagnostic patterns are highly distinguishable and form a potential basis for a phenomenological classification of psychiatric disorders that can be used with common understanding across national and language boundaries. The five major syndromes derived from analyses of American and German-speaking psychiatrists’ diagnostic concepts have been described here as core schizophrenia (without florid symptoms), florid schizophrenia, paranoid, depressive, and manic syndromes. It is interesting to note that these same major syndromes have been identified in empirical profile cluster analyses of actual patient profiles from the American and the French psychiatric populations, except that in the analyses of actual patient profiles the depression syndrome tends to split into three phenomenologically distinct types that have been described as anxious, retarded, and agitated (or hostile) depressive types. The general congruence of the major syndrome patterns derived from diagnostic stereotypes with the major syndromes identified by empirical clustering of patient
DIAGNOSTIC
117
CONCEPTS
Table 6.
Prototype
Profiles for Five Major Syndromes of Both American COW
Schizophrenia Somatic
concern
Anxiety Emotional
withdrawal
Represented
and German-speaking
Florid Schizophrenia
in Diagnostic
Concepts
Psychiatrists*
Paranoid Syndrome
Depression
Manic Excitement 1.5
3.2
3.9
3.2
4.7
2.8
4.4
3.9
5.3
1.4
5.1
4.4
3.4
3.8
2.0 4.1
4.3
4.7
3.1
3.0
Guilt feelings
?.l
2.7
2.0
4.9
1.4
Tension
2.8
4.3
4.0
4.0
5.2
Conceptual
disorganization
Mannerisms-posturing
3.6
3.5
2.1
2.3
2.8
Grandiosity
2.3
3.0
4.3
1.7
6.2
Depressive mood
2.3
2.8
2.1
5.5
1.3
Hostility
2.9
3.8
5.1
2.8
3.9
3.3
4.6
6.1
3.0
2.5
2.7
4.6
2.6
2.3
1.7
Motor retardation
3.6
2.5
1.6
4.5
1 .o
Uncooperativeness
3.5
3.7
4.0
3.1
3.8 2.9
Suspiciousness Hallucinatory
behavior
Unusual thought Blunted affect *Note extremely
that
content
3.9
5.4
5.0
3.4
5.2
3.6
2.7
2.7
ratings are scored on l-7
scale for
levels of severity
ranging from
1.6 not present to
severe.
profiles encourages us to say that these patterns do appear to represent the major phenomenologically distinct types that are present in psychiatric populations of several different countries. REFERENCES 1. Overall JE, Gorham DR: A pattern probability model for classification of psychiatric patients. Behav Sci 8:108-l 16, 1963 2. Overall JE: A configural analysis of psychiatric diagnostic stereotypes. Behav Sci 8: 21 I-219, 1963 3. Overall JE, Hollister LE: Computer procedures for classification of psychiatric patients. JAMA 187:583-588, 1963 4. Overall JE, Gorham DR: The brief psychiatric rating scale. Psycho1 Rep 10:799-812, 1962 5. Committee on Nomenclature and Statistics of the American Psychiatric Association: Diagnostic and Statistical Manual: Mental Disorders. Washington, American Psychiatric Association Mental Hospital Service, 1952 6. Pichot P, Bailly R, Overall JE: Les sttrCotypes diagnostiques des psychoses chez les psychiatres francais: Comparaison avec les
stereotypes americains. Proceedings of the 5th International Congress of the Collegium Internationale Neuro-Psycho-Pharmacologicum, 1966 7. Pichot P: La nosologie psychiatrique et le diagnostic par ordinateur. La Presse Medicale 75~1269-1274, 1967 8. Engelsmann F: Psychiatrickt posuzovaci stupnice a metody SkfilovQni. Report Vyzkumn); Ustav Psychiatrick$. Praha 8-Bohnice. 1967 9. Giberti F, Rossi R, Delmonte cetti classificative diagnostici tra Italiani. Archivio Neuropsychiatrica
P, et al: Congli psichiatri (in press)
10. Overall JE, Klett CJ: Applied Multivariate Analysis. New York, McGraw-Hill, 1972 Il. Overall JE: Historical and sociocultural factors related to the phenomenology of schizophrenia, in Siva Sankar DV (ed): Schizophrenia: Current Concepts and Research. Hicksville, N.Y., PJD Publications, 1968
Concepts Among Psychiatrists
John E. Overall and Hanns Hippius
T
HIS ARTICLE is concerned with an investigation of the nature of diagnostic concepts employed by psychiatrists in Germany, Austria, and Switzerland. The study was designed to evaluate the validity of a standard rating scale for description of differences among the German diagnostic classes, to provide prototype profiles that should facilitate understanding of the German nomenclature by English-speaking psychiatrists, and to study relationships between diagnostic concepts held by German-speaking and American psychiatrists. In each modern country a collection of diagnostic concepts has developed or has been adopted to span the range of psychopathology recognized by psychiatrists in that country. Diagnostic labels are abbreviated designations for complex patterns of psychopathology. Associated with each different diagnostic classification is the conception of a typical patient, or, as we shall call it, a diagnostic stereotype. By studying the diagnostic concepts, or stereotypes, held by psychiatrists in a particular region of the world, one can gain insight into the nature of psychopathology as it is recognized in that cultural setting. Thus the present study of diagnostic stereotypes held by German-speaking psychiatrists should provide a meaningful description of types of psychiatric disorders that are recognized in the academic and cultural context of German-speaking Central Europe. The translation of abstract and complex diagnostic nomenclature from one language to another poses a difficult problem. In this research we have approached the problem by reducing such complex concepts to more basic, simple, symptomdescriptive terminology. The symptom and behavior constructs of the Brief Psychiatric Rating Scale (BPRS) were chosen to provide a standard descriptive vocabulary subject to precise translation for use by psychiatrists in different countries.’ Most of the rating constructs in the BPRS involve nontechnical terms that exist in the everyday language of any western country. The few more technically psychiatric terms, such as hallucinatory behavior and blunted affect, have such universally recognized significance among professionally trained individuals that we believe good translation to be possible. Even these more specialized terms are also elaborated in the everyday vernacular in the rating scale itself. In short, the validity of the approach that we have taken to the problem of comparing diagnostic concepts held by psychiatrists in different countries rests on reduction of the complex diagnostic concepts to simple symptom-descriptive terms and the accurate translation of those basic terms. We believe that we have accomplished this task adequately to provide for meaningful examination of diagnostic concepts held by
From the University of Texas Medical Branch, Galveston, Tex., and Universitiit Miinchen, Germany. John E. Overall, Ph.D.: Professor, Universiiy of Texas Medical Branch, Galveston, Texas. Hams Hippius, M.D.: Professor and Dire&or. Psychiatrische Klinik und Poliklinik der Universitiit Miinchen. Germany. @ I974 by Grune & Stratton, Inc. Comprehensive Psychiatry. Vol. 15, No. 2 (March/April). 1974
103
104
OVERALL
AND
HIPPIUS
German-speaking psychiatrists and comparisons between the German and American nomenclatures. The study described in this article was patterned after similar studies previously done in the United States, France, Czechoslovakia, and Italy. The same standard symptom-descriptive terminology was used in all studies to facilitate comparisons of diagnostic nomenclatures. In the United States, Overall and associates2-4 conducted investigations using the BPRS’ to characterize similarities and differences among diagnostic stereotypes represented in the APA standard nomenclature.” Thirteen functional psychotic types were found to cluster into four major groups: schizophrenias, depressions, manias, and paranoid syndromes. While there was some suggestion of differentiation within the schizophrenia cluster, the phenomenological differences between the four major profile groups were much greater than differences within the groups. In France, Pichot and associate@’ completed a study of French diagnostic stereotypes using a careful translation of the BPRS. The study was perhaps particularly important in France because at that time there was no official standard nomenclature. Consistency among French psychiatrists in the conceptions of 12 diagnostic types was demonstrated. From the point of view of American psychiatry, the study was important because it made evident certain differences in meaning for apparently similar diagnostic terminology. Diagnostic labels in French that sound like familiar American labels have in fact quite different meanings. In addition, the results from the study emphasized the uniqueness of the hallucinatory psychosis, for which there is no counterpart in the American nomenclature. A similar study was undertaken in Czechoslovakia by Engelsmann and associates8 using a Czechoslovak translation of the BPRS. In this study the World Health Organization international classification was examined. Perhaps largely due to the standard diagnostic concepts considered, the relationships between results obtained in this study and those obtained from the study completed in the United States were quite good. The Czechoslovak study has perhaps its primary importance in providing quantitative rating-scale definitions of the WHO international classification concepts. An identically designed study undertaken in Italy has recently been completed.9 The results again revealed four major types of psychiatric disorders represented among the 12 Italian diagnostic concepts that were considered. In view of the series of similar studies completed in different countries, it seemed important to examine in the same manner diagnostic concepts held by Germanspeaking psychiatrists. The BPRS was translated into German for use in describing the symptom and behavior characteristics of 12 diagnostic types. The 12 types were selected on the basis of general familiarity and frequent use, with consideration being given to spanning the full range of major psychopathology. The purposes of the study were to evaluate the adequacy of the BPRS for characterizing differences among German diagnostic classes, to provide symptom-descriptive profiles representing the major German diagnostic classes, and to examine relationships between the German and American psychiatric concepts as they are represented in BPRS symptom rating profiles.
DIAGNOSTIC
105
CONCEPTS
METHOD A total of 108 German-speaking psychiatrists from Germany, Austria, and Switzerland participated as expert judges in this study. Of the total group of experts, 90 were employed in university hospitals and I8 in the Department of Psychiatry of the Max-Planck-lnstitut, which is somewhat similar to the American NIMH. All were experienced clinicians familiar with the diagnostic nomenclature with which the investigation was concerned. Each psychiatrist was provided with I2 rating forms. At the top of each form was typed the name of a psychiatric diagnostic class. The judge was asked to conceive of a typical patient of the type named at the top of the form and to provide a quantitative symptom profile to describe that type of patient by indicating level of severity for each of the I6 symptom rating constructs. Multivariate analyses were undertaken to examine similarities and differences between the diagnostic profiles and to investigate the extent of agreement among psychiatrists in the nature of symptom profiles that they provided to portray various diagnostic groups. Multiple discriminant analysis and Mahalanobis DZ statistics were employed for this purpose. A mean prototype profile was computed to describe each diagnostic type. A distance function classification procedure was used to assess similarities of individual BPRS profiles to the 12 diagnostic prototypes. The stereotype profiles provided by different psychiatrists were analyzed using this program to determine the degree of consensus within diagnostic class and the extent of recognizable distinction between profiles that were supposed to represent different diagnostic classes. Following the analyses of consistencies of the diagnostic stereotypes held by different psychiatrists and the subsequent definition of prototype profiles representing I2 German diagnostic classes, multivariate analyses of relationships between German and American diagnostic concepts were undertaken. A matrix of O* distance function coefficients was computed, and an empirical cluster analysis was employed to classify the combined German-American diagnostic prototypes according to similarities and differences in profile patterns. The purpose of this analysis was to determine whether each major phenomenological type is represented in both German and American diagnostic classifications. Finally, a Q-type factor analysis of profile pattern correlations was undertaken in an effort to identify a basic set of profile patterns that should be adequate to represent the major phenomenological distinctions that are common to both the German and American nomenclatures, Not all diagnostic distinctions are based on symptom and behavior characteristics. It was considered worthwhile to determine how many and what types of symptom and behavior patterns are highly distinguishable in the diagnostic conceptions of the different countries. Even though diagnostic classification systems may not correspond perfectly, it is still possible that the same basic phenomenological subtypes exist in the clinical populations. Identification of the basic phenomenological distinctions that are common to diagnostic nomenclatures of different countries should provide some indication of the nature of underlying disorders that appear in substantially similar form across national and cultural boundaries.
RESULTS
Multiple discriminant analysis is a method for studying the configural relationships among several diagnostic groups in a reduced discriminant function space. The primary implication of the analysis in this instance was determination of the number of significant dimensions of symptom profile difference separating the 12 diagnostic stereotypes in the minds of German-speaking psychiatrists. The number of significant discriminant dimensions provides information concerning the minimum number of discriminably different symptom profile patterns represented among the 12 diagnostic groups. One dimension is required to describe differences between two groups, two dimensions may be required to account for differences between three groups, three dimensions may be required to account for differences between four groups, and so on. Several groups can differ along a single continuum; however, if an analysis reveals that k dimensions are required to represent all significant group differences, then there must be at least k + 1 discriminably different groups.
OVERALL
106
AND
HIPPIUS
In the analysis of diagnostic profiles provided by German-speaking psychiatrists, the maximum number of discriminant dimensions would be 11 if each of the 12 types were to differ significantly from the others. The 11 roots of the determinantal equation ) B - XW ( = 0 were 4627, 2644, 2223, 1168, 763, 292, 106, 74, 50, 30, and 10, so that the trace or sum of roots was 11987. The sum of all roots is approximately distributed as a chi-square statistic with p(k-I) degrees of freedom, where p = 16 symptom measurement variables and k = 12 groups.‘O The x2 = 11987 with 176 df is recognized to be highly significant. This overall test supported the conclusion that among the 12 diagnostic types are at least some types that psychiatrists consistently conceive as different from the others in terms of BPRS symptom profile patterns. As described by Overall and Klett,‘O a strategy for determining the number of significant discriminant dimensions involves testing the significance of the sum of all possible roots, then subtracting out the first root and testing the significance of the residual to determine whether any other dimensions of group difference need be considered, then subtracting out the second root and repeating the test, and so on until the residual is not significant. At any stage, a significant x2 test is interpreted to mean that at least one more dimension of group difference is significant and has not adequately been represented in the previously defined discriminant functions. Each additional significant discriminant function suggests the presence of at least one additional diagnostic group that can be distinguished from the others in terms of BPRS symptom rating profiles.
Sum of all roots less X, less X, less X, less h, less h5 less X, less h, less X, less X, less h,,
X2
df
P
11987 7360 4716 2493 1325 562 270 164 90 40 10
176 150 126 104 84 66 50 36 24 14 6
0:oo 1 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 N.S.
The series of x2 tests performed on residual variances remaining after partialling out successive roots of the determinantal equation yielded consistently significant results until after the tenth root was subtracted out. The x2 = 40 with 14 df obtained after partialling out the first nine roots suggests that a tenth dimension is required to account for all discriminable differences among the 12 diagnostic types. The x2 = 10 with 6 df fails to support the existence of an eleventh significant dimension. These results suggest that at least 11 of the 12 diagnostic concepts were consistently attributed different BPRS profile patterns by the expert judges. Mean BPRS profiles for the 12 diagnostic types computed from the rating profiles provided by the several psychiatrists are presented in Table 1. These mean profiles will be accepted as prototypes of patients who are considered typical of the 12 diagnostic classes. Although it is possible to gain some insight into the particular
simplex
3.3
4.8
Endoreaktive
Mischpsychose
1.3
Manie
Dysthymie
5.2
2.9
3.0
2.7
Endogene Depression
Persijnlichkeitswandel
Schizophrener
Schizophrenic
Hebephrene
Schizophrenia
6.0
CoenPsthetische
Schizophrenic
2.4
3.0
3.1
2.4
Paranoia
Schizophrenic
peranoid-
peranoide
katatone
halluzinatorische
Schubfiirmige
Schizophrenic
Schubformige
Schizophrenic
Schubfiirmige
4.3
5.0
1.2
6.1
2.6
2.8
2.7
4.7
3.7
4.5
4.6
3.9
3.5
2.7
1.4
3.7
5.4
5.3
4.7
4.0
2.7
4.0
4.0
6.0
3.2
1.2
3.3
1.3
4.2
3.6
4.8
3.0
1 .6
4.6
3.7
5.2
3.4
3.6
1 .l
6.0
1.6
1.9
1.7
2.0
1.6
2.1
2.1
2.0
Table 1. Meen BPRS Symptom
4.0
2.8
4.7
2.8
2.3
2.5
3.2
3.3
3.2
4.6
4.3
6.0
2.6
1.3
2.3
1.3
4.2
3.2
4.6
2.5
1.9
3.2
2.8
5.5
2.3
1.1
6.0
1.0
2.1
1.8
2.8
1.5
3.1
3.6
3.3
2.6
Profiles for 12 German
4.0
5.0
1 .l
6.4
2.2
2.6
2.2
3.1
1.9
1.9
2.0
2.0
3.1
i .9
3.0
1.3
3.0
2.6
3.0
2.5
4.9
4.5
4.6
3.7
Diagnostic
3.9
I .a
1.9
1.9
3.5
2.8
2.8
3.3
6.1
5.8
6.1
3.8
Types
3.0
I .o
1.2
1.3
2.5
1.9
2.8
4.4
1.4
6.1
2.8
4.2
2.9
4.1
1.0
5.9
4.6
4.8
4.0
3.1
1.5
2.0
2.0
4.0
2.9
2.1
3.0
2.1
3.6
3.6
3.9
2.8
3.1
3.8
3.4
5.1
3.4
1.4
2.0
2.4
4.0
3.3
4.3
4.8
4.2
5.6
5.2
4.6
2.6
2.1
1.3
2.6
5.9
5.3
5.3
3.6
1.9
2.8
2.9
3.2
2
5
0’
8
0
Y
z
z
E
OVERALL AND
108
HIPPIUS
groups that are most distinguishable by examining mean scores on the various discriminant continua, the substantial number of significant discriminant functions identified in this analysis lessens the utility of that approach. In view of the number of significant group differences, a more meaningful question concerns which particular diagnostic concepts are not discriminably different in terms of associated BPRS profiles. To answer this question, a matrix of Mahalanobis D2 coefficients was calculated to provide an index of difference between each pair of diagnostic groups. The D2 statistic can be converted to an F ratio to provide a test of the significance of the difference between multivariate group means relative to the variability of profiles provided by different psychiatrists.l” For the degrees of freedom that are available, the minimum value of D2 that should be taken as evidence of consistent differences in the psychiatrists’ stereotypes of two diagnostic classes is approximately D2 > 0.75. The matrix of D* coefficients relating all pairs of the 12 diagnostic groups is presented in Table 2. From examination of the Dz coefficients, one is led to conclude that the expert judges attributed a distinct BPRS profile pattern to each diagnostic class with enough consistency to result in statistical significance. Statistical significance in this study of diagnostic stereotype profiles is an indication that the differences between the main profiles are substantially large relative to the variability of profiles provided by different judges. The results are accepted as confirming that the BPRS symptom rating constructs provide an adequate vocabulary for describing differences among stereotypes of diagnostic classification as conceived by German-speaking psychiatrists. Apart from the question of statistical significance, one can gain insight into the relative similarities and differences among diagnostic concepts by examining the D2 coefficients. It is apparent that groups 7 and 8 tended to be least discriminable in Table 2. D2 Distances Between 1.
-
15.8
2.
15.8
3.
13.3
Diagnostic
Prototype
Profiles
12.3
12.4
43.7
31.5
31.4
15.7
8.9 14.0
13.8
12.8
40.6
29.5
26.8
8.9
17.1
13.6
16.2
20.3
17.5
51.6
35.2
37.0
12.5
13.3
28.2
20.4
-
7.3
4.2
7.3
-
13.4
4. 28.2
4.2
17.1
-
24.2
22.3
20.0
19.8
42.7
28.2
26.5
13.1
5. 20.4
15.7
13.6
24.2
-
14.5
13.3
14.6
30.5
41.6
18.2
11.1 9.8
6.
8.9
14.0
16.2
22.3
14.5
-
3.0
2.0
35.3
24.0
22.8
7.
12.3
13.8
20.3
20.0
13.3
3.0
-
1.4
24.9
28.9
15.2
8.1
8.
12.4
12.8
17.5
19.8
14.6
2.0
1.4
-
34.7
33.0
23.6
11.2
9. 43.7
6.2
16.9 24.4
34.0
34.0 _
24.4
8.7
40.6
51.6
42.7
30.5
35.3
24.9
34.7
-
56.0
10.
31.5
29.5
35.2
28.2
41.6
24.0
28.9
33.0
56.0
-
11.
31.4
26.8
37.0
26.5
18.2
22.8
15.2
23.6
6.2
12.
13.4
8.9
12.5
13.1
11.1
9.8
8.1
11.2
16.9
1 = Schubformige 2 = Schubformige
katatone Schizophrenic. paranoide Schizophrenic.
3 = Schubformige
paranoid-halluzinatorische
4 = Paranoia. 5 = Coenasthetische 6 = Hebephrene
Schizophrenic.
Schizophrenic.
7 = Schizophrenia
simplex.
8 = Schizophrener
Personlichkeitswandel.
9 = Endogene 10 = Manie.
Depression.
11 = Endoreaktive 12 = Mischpsychose.
Dysthymie.
Schizophrenic.
8.7 -
DIAGNOSTIC
CONCEPTS
109
terms of BPRS symptom profiles, and the fact is that simple schizophrenia and schizophrenic personality are not easily distinguishable in anybody’s conception. Groups 9 and 10 (depression and mania) are the most discriminable, and groups 9 and 3 (depression and paranoid-hallucinatory schizophrenia) are next most discriminable. From this type of casual inspection, we recognize three major discriminable types-depressive, manic, and schizophrenic. An empirical profile cluster analysis was used to classify the diagnostic patterns into syndromes or major phenomenological classes on the basis of similarities and differences represented by the D2 coefficients. The computer analysis revealed relatively homogeneous clusters of diagnostic types that differed substantially from one another. Although the patterns that were classified into each cluster differed to a statistically significant extent, the differences within clusters tend to be small relative to the differences between clusters. Four major phenomenological distinctions represented in the diagnostic concepts of German-speaking psychiatrists were found to be the following: Core Schizophrenias
Hebephrene Schizophrenic Schizophrenia simplex Schizophrener PersGnlichkeitswandel Paranoid Syndromes
Schubfiirmige paranoide Schizophrenic Paranoia Depressive Syndromes
Endogene Depression Endoreaktive Dysthymie Mania
Manie The distinctness of these four profile patterns can be appreciated by inspection of the prototype profiles in Table 1, and the cluster grouping can be verified by examination of the Dz coefficients in Table 2. Diagnostic profiles that were not included in one of the four distinct categories by the computer analysis can be seen to fall between the identified clusters. The similarities of the four major phenomenological classes to those identified among American, French, Czechoslovak, and Italian diagnostic stereotypes should be noted. The diagnostic concepts of German-speaking psychiatrists appear to span the same major domains of psychopathology that are represented in diagnostic concepts of psychiatrists in other countries. The cluster grouping suggests that most of the differences between diagnostic concepts of the German-speaking psychiatrists should be susceptible to representation in .a simple three-dimensional model. This is suggested because a maximum of three dimensions is required to represent the multivariate profile differences among any four groups. Referring back to the multiple discriminant analysis that was undertaken as the initial analysis of these data, it can be verified that 79% of the total discriminable variance among the 12 diagnostic groups was accounted for by the first three discriminant functions. Recognizing the uniqueness of the manic profile pattern, the manic group can be left out to reduce the required
110
OVERALL
AND
HIPPIUS
dimensions for an adequate discriminant function model to two. Although additional dimensions are statistically significant, most of the differences between schizophrenic, paranoid, and depressive syndromes can be represented in only two dimensions. A simple two-dimensional model should provide a convenient representation of relationships among the diagnostic concepts in the BPRS symptom profile context. A second multiple discriminant analysis was accomplished with the manic group omitted for the purpose of developing a geometric model to represent relationships among the remaining 11 diagnostic concepts in a two-dimensional space. The results are shown in Fig. 1, where the grouping previously derived from cluster analysis of D2 coefficients is clearly verified. In the geometric model, distances between points represent the magnitudes of overall profile differences. Symptom vectors have been inserted into the discriminant function space to provide an indication of the unique symptom characteristics associated with each region. The computer program used for the analysis and the method of positioning symptom vectors in the discriminant function model have been presented by Overall and Klett.‘O The first discriminant function separated the depressive profile patterns from all others in the BPRS measurement space. It is represented by the vertical axis in Fig. 1. The second discriminant function, represented by the horizontal axis, separated the core schizophrenic patterns from the paranoid patterns. Even in the reduced two-dimensional projection, the three major diagnostic types appear
4 3
SUSPICIOUSNESS
4 .
\
-’ UNUSL 2 THOlJ( . 1 HOSTILITI
HALLUCINATORY
f
p&PT ”
!
WITHDRAWAL
\
DEPRES MOOD
RETARDATION
Fig. 1. Conffgural relationships among 11 diagnostic stereotypes with vectors indicating target symptoms in various groups: (1) schubfiirmige katatone Schizophrenic, (2) rchubfiirmige paranoide Schizophrenic, (3) schubf6rmige paranoidhalluzinatorische Schizophrenic, (4) Paranoia, (6) coeniisthetische Schirophrenie, (6) hebephrene Schizophrenia, (7) Schizophrenia simplex, (8) schizophrener Persiinlichkeitswandel, (9) endogene Depression, (101 endoreaktive Dysthymie, (11) Mischpsychose.
DIAGNOSTIC
111
CONCEPTS
phenomenologically distinct. As indicated by the symptom vectors that were inserted into the discriminant function model, BPRS symptoms of anxiety, guilt feelings, and depressive mood tended to be present at relatively high levels in the depressive profile patterns. Hostility, suspiciousness, and unusual thought content marked the paranoid profile patterns. Conceptual disorganization, mannerisms and posturing, blunted affect, and emotional withdrawal were relatively more prominent in the core schizophrenic patterns. These phenomenological distinctions can readily be verified by reference to the mean profiles that were presented in Table 1. As a method of examining in greater detail the discriminability of rating profiles provided by the expert judges to represent the 12 diagnostic types, a computer diagnostic classification program was used. lo The program calculates an estimate of the probability with which any particular BPRS profile belongs in each of the several specified populations, and the profile is then assigned to the diagnostic category in which it is judged to have the highest probability of occurrence. In this application of the method, the diagnostic populations were specified to have means equal to the mean profiles shown in Table 1. In effect, the program determined whether each individual profile was more like the mean for the diagnostic group that it was said to represent or more like the mean for some other diagnostic group. If all 108 psychiatrists had been perfectly consistent in recognizing symptom and behavior differences among the diagnostic classes, there would be no overlap in the distributions and the computer program should be able to correctly assign all profiles. Where the computer assigned a profile to the wrong diagnostic class, it was because the profile was more like the pattern designated by a majority of the judges to represent the alternative diagnostic class. Thus the diagnostic classification program provided a method of examining consistencies among the psychiatrists’ conceptions of the diagnostic profile patterns, as well as the discriminability among the different types. Results from computer assignment of the individual profile patterns among the 12 diagnostic groups are presented in Table 3. In each row of the table are tallied profiles that were designated by the expert judges to represent one particular diagnostic type.3 The successive entries across each row indicate the computer assignment. For example, in the fourth row from the top are entered results from Table 3. Computer
Classification
of German
Diagnostic
Stereotype
Profiles
computer
r ._ ;
9.
12.
0
2
9
2
4
0
0
0
0
51
17
25
2
l
1
0
0
0
1
9 2
3.
4
10.
11.
8
4.0
7.
8.
1 1
4.
6.
2.
2.
3.
5.
1. 1.79
3
91
1
2
1
0
0
0
0
87
3
1
3
0
0
0 0
0
11
0
2
1
6
0
67
0
4
l
o
0
5
2
.m r :
5.
0
6.
12
2
0
0
0
52
14
20
0
2
3
3
z
7.
1
0
1
1
2
13
42
28
0
0
0
13
2 0
l 0
1 0
2 0
20 0
25 0
56 0
0 95
0
0
1
0
13
0
0
0
8.0 9.0
0
0
1
0
0
0
0
0
11.
0
0
0
0
1
0
0
0
18
105 0
68
5
12.
8
0
3
2
3
1
3
0
1
5
15
54
10.0
112
OVERALL
AND
HIPPIUS
computer classification of profiles that were offered by the psychiatrists to represent paranoia. The computer recognized 87 of them to be most like the group norm or prototype for paranoia. Eleven were found by the computer to be more like the prototype for paranoid schizophrenia, a reasonable confusion, and only nine of the reputed paranoia profiles were assigned by the computer to one of the nonparanoid categories. Entries in other rows of the table can be evaluated in a similar fashion. Examination of the computer assignments of individual profiles provides another approach to understanding the relative similarities and differences in conceptual stereotypes of psychiatric disorders. The computer does not actually make mistakes in evaluating similarities of profiles. When the computer misclassifies a profile, it is because the profile provided by a particular expert to represent his conception of a given diagnostic type is more like that which the majority of experts specified for another type. The entries in Table 3 reveal that most diagnostic categories were clearly discriminable. Some degree of confusion between types 2, 3, and 4 is apparent. Types 6, 7, and 8 form another cluster within which distinctions are not highly apparent. Finally, some overlap between types 9 and 11 is evident. The catch-all Mischpsychose tends to be least distinct from all other groups. These conclusions are supported by the proximities of the several diagnostic groups in Fig. 1 and by the D2 coefficients in Table 2. Having verified that the BPRS is adequate for description of differences in conceptual stereotypes of diagnostic classification among German-speaking psychiatrists and having evidence of considerable agreement among the psychiatrists concerning the distinctive features of each type, analyses were next undertaken -to evaluate relationships between diagnostic concepts of German-speaking and American psychiatrists. Prototype profiles representing 13 diagnostic types described in the standard American Psychiatric Association nomenclature have been presented previously.3 A matrix of D2 (distance function) coefficients was computed to represent relationships between the German and American diagnostic profiles. For these calculations, the variability within profile groups was disregarded and the squared distance between each pair of diagnostic prototypes was calculated as the sum of squares of differences in mean scores on the 16 BPRS symptom rating variablese4 The 12 x 13 matrix of D2 coefficients relating each German diagnostic concept to each of the American diagnostic concepts is presented in Table 4. For each of the diagnostic concepts of German-speaking psychiatrists, one can identify the nearest equivalent diagnostic concepts in the American nomenclature. It is readily apparent that the paranoid-type profiles in the German-speaking psychiatrists’ conceptions are most like the paranoid types as conceived by the American psychiatrists. The core schizophrenic types in the German system are represented by profiles that are most similar to those in the core schizophrenic cluster within the American system. The depressive and manic patterns are obviously similar within the two diagnostic schemes. Although the same general patterns are present in similar form within the diagnostic conceptions of Germanspeaking and American psychiatrists, it does not appear feasible to establish a one-to-one correspondence between specific diagnostic classes on the basis of BPRS profile patterns alone. Such an attempt would lead to apparent discrep-
DIAGNOSTIC
113
CONCEPTS
Table 4. 1.
2.
3.
German
Diagnostic
Prototypes
4.
5.
6.
7.
8.
9.
10.
11.
12.
0
1. 116.6
45.4
78.5
14.5
85.2
84.4
82.0
89.2
157.8
29.5
93.8
59.1
g
2.
80.4
23.2
47.1
7.6
56.4
61.1
62.3
68.9
127.4
28.1
73.7
32.8
6
3.
55.4
10.9
la.3
14.6
42.6
48.8
59.9
57.7
143.3
44.5
96.4
32.3
5 o.
4.
27.0
13.4
15.5
33.1
17.5
24.5
34.5
34.9
94.0
56.6
64.0
11.6
5.
12.4
47.1
45.0
77.0
48.1
10.4
20.8
14.8
118.9
95.4
100.9
41.0
,; g
6.
34.6
48.1
41.1
74.8
47.3
16.3
35.8
25.1
161.2
74.2
112.1
51.4
62.0
66.0
48.4
2 .E
a. 7.
82.0 86.4
55.5 68.2
92.8 81.2
61.2 38.3
46.9 55.4
44.7 33.4
33.8 22.4
45.0 30.0
112.0 93.5
41.7
44.6
33.2
9.
39.4
27.0
36.8
36.8
24.7
12.1
15.1
14.8
101.0
49.6
64.6
21.1
g
10.
51.9
24.5
38.8
27.4
24.1
36.8
36.3
46.0
61 .4
42.4
33.4
5.1
.g 11. f 12.
75.1 94.9
59.8 78.3
82.1 107.0
67.8 80.0
32.1
60.0
45.0
62.7
18.0
105.0
15.8
16.5
8.1
118.0
10.7
26.3
a
97.2
69.3
88.7
51.4
195.0
4.3
122.0
73.4
13.
44.5 111.5
75.0
51.7
74.1
78.3
92.9
98.7
ancies that in the opinion of the present writers are due more to sampling variability than to true differences in diagnostic concepts. For example, the American “catatonic schizophrenia” profile is most similar to the German “hebephrenic schizophrenia” profile, although the German “catatonic schizophrenia” profile runs a close second. And from the point of view of the American nomenclature, the German “catatonic schizophrenia” pattern is much more similar to the American “catatonic” pattern than it is to any other. Thus, in spite of the fact that one would encounter difficulties in establishing a one-to-one equivalence between specific diagnostic types on the basis of BPRS profile patterns alone, the Dz coefficients do reveal a highly satisfactory correspondence of specific diagnostic concepts between the German-speaking and American psychiatrists. Factor Analysis of Relationships Among German and American Diagnostic Prototypes
Recognizing certain difficulties in the attempt to establish a meaningful one-toone equivalence for specific diagnostic concepts, it is perhaps more meaningful to ask what broader phenomenological distinctions tend to be represented in both the German and American nomenclatures. If it is assumed that the several diagnostic prototypes from both classification systems can be reduced to a relatively few basic patterns, what should those basic patterns be? Factor analysis can be used to study similarities among profile patterns in much the same way that it is used to study relationships among measurement variables. The product-moment correlation between two multivariate profiles provides an index of the similarity of the profile patterns, with elevation and variability differences eliminated.5 The factors derived from analysis of a matrix of such profile correlations can be conceived to represent hypothetical pure types to which the observed profile patterns relate in varying degree. The matrix of factor loadings resulting from an analysis of (Q-type) profile correlations contains indices of similarity between the observed profiles and the underlying pure types. The analysis can thus result in an understanding of the number and nature of basic profile patterns represented among the larger set of prototype profiles. The 12 diagnostic prototypes from German-speaking psychiatrists and 13 pre-
114
OVERALL
AND
HIPPIUS
viously published diagnostic prototypes from American psychiatrists were intercorrelated to yield a 25 x 25 Q-type correlation matrix. The Q-type correlations were first subjected to an orthogonal powered vector factor analysis,‘O and from the results a marker profile was chosen to represent each distinct factor. The marker profiles selected were the diagnostic prototypes with largest projection on each orthogonal factor. The marker profiles were then used to initiate a marker variable analysis, which stabilizes on an oblique simple structure in which each primary factor is the principal axis of a cluster of profiles that relate empirically to the marker profiles.” A total of six factors were defined in the preliminary orthogonal factor analysis. This was interpreted to mean that the diagnostic prototypes from the two countries include at least six higher order syndromes that are represented by two or more diagnostic prototypes with relatively similar profile patterns. Interest in the analysis was in determining whether each cluster of similar profiles included representatives from both German and American diagnostic schemes. The prototype profile having the greatest relationship to each of the six factors was selected as a marker for one of the distinct underlying patterns. As it happened, the six marker profiles chosen in this manner were all from among the American prototypes. They were as follows, in the order of selection: 1. Schizophrenic reaction, simple type 2. Paranoid state 3. Psychotic depressive reaction 4. Manic-depressive, manic type 5. Schizophrenic reaction, catatonic 6. Schizophrenic reaction, hebephrenic It will be noted that the first four marker profiles clearly represent the core schizophrenic, paranoid, depressive, and manic clusters previously identified. The last two marker profiles suggest that the (American) catatonic and hebephrenic patterns deviate in a consistent manner from the core schizophrenic type across the combined sets of prototypes, resulting in two additional specific types. Using the six profiles indicated above as markers, a Q-type marker variable factor analysis was accomplished to provide indices of relationships of the 25 prototype profiles to six underlying pure type patterns for which the six marker profiles were tentative approximations. The oblique reference structure presented in Table 5 indicates the degree of relationship of the prototype profiles to each pure type. In the Q-type factor solution, Factor I is associated with the core schizophrenic pattern. It is represented in three obviously similar prototype profiles from each diagnostic scheme. It should be noted that the core schizophrenic pattern tends to be represented in the more endogenous, chronic, and less floridly psychotic diagnostic groups. Factor II is associated with paranoid type profile patterns. This distinct configuration appears in three of the American prototypes and two of the German prototypes. Factor III, identified with the depressive profile pattern, is represented in three of the American prototypes and three of the German prototypes. Factor IV is identified with the manic profile pattern, and it is represented once in each collection of diagnostic prototypes. Factor V is associated with acute, active, florid psychosis, as distinct from the core schizophrenic types. Finally, Factor VI is identified with the catatonic profile pattern that appears in sub-
DIAGNOSTIC
Table 5.
115
CONCEPTS
Reference
Structure
Derived from O-Type American
Diagnostic
Factor Analysis of Combined
German
and
Prototvpas I.
II.
III.
Paranoia
.06
e
-.08
Paranoid state
.oo
&I
IV.
v.
VI.
American
Schizophrenic
reaction,
paranoid
Schizophrenic
reaction,
acute undifferentiated
Schizophrenic
reaction,
catatonic
Schizophrenic
reaction,
hebephrenic
Schizophrenic
reaction,
simple
Schizophrenic
reaction,
chronic
Schizophrenic
reaction.
residual
Schizophrenic
reaction,
schizoaffective
- .02
type
-.Ol
-.I4
-.02
.04
.24
-.02
-.I2
.25
-.25
-.30
.73
-.06
_73
undifferentiated
.48
.09
_52 -.06
- .03
-.05
.04
.23
-.ll
.I6
29
-.15
-.08
.02 .63 .Ol
.07
.44
.oo
02
-.07
.28
-.25
.13
.20
.Ol
.35
-.I3
.67
.36
.49
-.I3
Psychotic depressive reaction
.Ol
-.07
.77
depressive type
.Ol
-.02
.71
Manic-depressive,
manic type
.04
-.08
.04
.oo
Manic-depressive,
- .oo
-.I6
.I3
-.15
.08 -.04
.06
-.Ol
Z
.04
-.14
.09
.03 -94 _61
.Ol
.05
.15
.08
.63
.lO
.ll .I3
German Schubformige
katatone
Schubformige
paranoide
Schizophrenic
Schubformige
paranoid-halluzinatorische
- .04 .02
Schizophrenic
Schizophrenic Paranoia Coenasthetische
Schizophrenic
.02
.I2
sr,
.lO
-.29
.28
-.07
.85
.I4
-.06
-.05 -.12
2
.02
-.19
-.21
.22
-.19
.58
-.21
-.03
.14
-30
.14
-.I6
-.20
-.ll
-.I5
-.05
-.Ol
-.05
-.I3
-.09
.12
-.12
simplex
_67
06
Schizophrener
Personlichkeitswandel
_61
99
.05
-.06
.58
.oo
-64
ol
.06
-.Ol
_62
-Z5
_ss
-.02
Endogene
Schizophrenic
Depression
Manie Endoreaktive
Dysthymie
-.13
Mischpsychose
-.09
-.09
.55
Schizophrenia
Hebephrene
.12 -.12
.24
.I3 -.23
.70
.I8
.12
.lO
stantially similar form in the diagnostic conceptions of both German-speaking and American psychiatrists. It should be noted that the American hebephrenic pattern, whieh served as marker profile in the definition of factor V, did not remain the most prominent example of the florid psychotic type in the final rotated marker variable solution. The Aorid psychotic prototype is more similar to the American acute undifferentiated profile. The factor analysis of profile pattern relationships led to recognition of the following major syndrome equivalencies: German
American
Core Schizophrenic Syndromes Schizophrenic reaction, simple Schizophrenic reaction, chronic undifferentiated Schizophrener Persiinlichkeitswandel Schizophrenic reaction, residual
Hebephrene Schizophrenic Schizophrenia simplex
Paranoid Syndromes
Schubfijrmige paranoide Schizophrenic Paranoia
Paranoia Paranoid state Schizophrenic reaction, paranoid
OVERALL
116
AND
HIPPIUS
Depressive Syndromes
Schizophrenic reaction, schizoaffective Psychotic depressive reaction Manic-depressive, depressed
Mischpsychose Endoreaktive Dysthymie Endogene Depression
Manic Syndromes
Manic-depressive,
Manie
manic
Florid Schizophrenic Syndromes
SchubfGrmige paranoide Schizophrenic Halluzinatorische Schizophrenic Coen%thetische Schizophrenic
Schizophrenic reaction, acute undifferentiated Schizophrenic reaction, hebephrenic Schizophrenic reaction, schizoaffective
Catatonic Syndromes
Schubfijrmige katatone Schizophrenic
Schizophrenic reaction, catatonic
The results from the Q-type factor analysis of the combined German and American diagnostic prototype profiles revealed six distinct types of profile patterns, rather than the four previously noted in analyses of the separate sets of data. This came about because similarities in patterns across the two systems produced additional distinct clusters that could not be recognized as such in either set alone. Specifically, the schizophrenic subtypes were found to include three distinct profile patterns across both diagnostic systems: core schizophrenic, florid schizophrenic, and catatonic patterns. In addition, of course, there is the paranoid syndrome that includes paranoid schizophrenia. Thus separate and distinct profile patterns that are quite comparably conceived by both German-speaking and American psychiatrists include manic, depressed, paranoid, core schizophrenic, florid schizophrenic, and catatonic schizophrenic patterns. The catatonic pattern, while distinct enough to form a separate cluster, can be observed to be closest to the florid schizophrenic category. In view of the rather specific nature of the distinguishing features, we would prefer not to emphasize the catatonic pattern as a distinct major phenomenological subtype, although there is an empirical basis for doing so. Prototype BPRS profiles representing the remaining five major types of psychiatric disorders, as derived from the combined German and American diagnostic stereotype data, are presented in Table 6. These major diagnostic patterns are highly distinguishable and form a potential basis for a phenomenological classification of psychiatric disorders that can be used with common understanding across national and language boundaries. The five major syndromes derived from analyses of American and German-speaking psychiatrists’ diagnostic concepts have been described here as core schizophrenia (without florid symptoms), florid schizophrenia, paranoid, depressive, and manic syndromes. It is interesting to note that these same major syndromes have been identified in empirical profile cluster analyses of actual patient profiles from the American and the French psychiatric populations, except that in the analyses of actual patient profiles the depression syndrome tends to split into three phenomenologically distinct types that have been described as anxious, retarded, and agitated (or hostile) depressive types. The general congruence of the major syndrome patterns derived from diagnostic stereotypes with the major syndromes identified by empirical clustering of patient
DIAGNOSTIC
117
CONCEPTS
Table 6.
Prototype
Profiles for Five Major Syndromes of Both American COW
Schizophrenia Somatic
concern
Anxiety Emotional
withdrawal
Represented
and German-speaking
Florid Schizophrenia
in Diagnostic
Concepts
Psychiatrists*
Paranoid Syndrome
Depression
Manic Excitement 1.5
3.2
3.9
3.2
4.7
2.8
4.4
3.9
5.3
1.4
5.1
4.4
3.4
3.8
2.0 4.1
4.3
4.7
3.1
3.0
Guilt feelings
?.l
2.7
2.0
4.9
1.4
Tension
2.8
4.3
4.0
4.0
5.2
Conceptual
disorganization
Mannerisms-posturing
3.6
3.5
2.1
2.3
2.8
Grandiosity
2.3
3.0
4.3
1.7
6.2
Depressive mood
2.3
2.8
2.1
5.5
1.3
Hostility
2.9
3.8
5.1
2.8
3.9
3.3
4.6
6.1
3.0
2.5
2.7
4.6
2.6
2.3
1.7
Motor retardation
3.6
2.5
1.6
4.5
1 .o
Uncooperativeness
3.5
3.7
4.0
3.1
3.8 2.9
Suspiciousness Hallucinatory
behavior
Unusual thought Blunted affect *Note extremely
that
content
3.9
5.4
5.0
3.4
5.2
3.6
2.7
2.7
ratings are scored on l-7
scale for
levels of severity
ranging from
1.6 not present to
severe.
profiles encourages us to say that these patterns do appear to represent the major phenomenologically distinct types that are present in psychiatric populations of several different countries. REFERENCES 1. Overall JE, Gorham DR: A pattern probability model for classification of psychiatric patients. Behav Sci 8:108-l 16, 1963 2. Overall JE: A configural analysis of psychiatric diagnostic stereotypes. Behav Sci 8: 21 I-219, 1963 3. Overall JE, Hollister LE: Computer procedures for classification of psychiatric patients. JAMA 187:583-588, 1963 4. Overall JE, Gorham DR: The brief psychiatric rating scale. Psycho1 Rep 10:799-812, 1962 5. Committee on Nomenclature and Statistics of the American Psychiatric Association: Diagnostic and Statistical Manual: Mental Disorders. Washington, American Psychiatric Association Mental Hospital Service, 1952 6. Pichot P, Bailly R, Overall JE: Les sttrCotypes diagnostiques des psychoses chez les psychiatres francais: Comparaison avec les
stereotypes americains. Proceedings of the 5th International Congress of the Collegium Internationale Neuro-Psycho-Pharmacologicum, 1966 7. Pichot P: La nosologie psychiatrique et le diagnostic par ordinateur. La Presse Medicale 75~1269-1274, 1967 8. Engelsmann F: Psychiatrickt posuzovaci stupnice a metody SkfilovQni. Report Vyzkumn); Ustav Psychiatrick$. Praha 8-Bohnice. 1967 9. Giberti F, Rossi R, Delmonte cetti classificative diagnostici tra Italiani. Archivio Neuropsychiatrica
P, et al: Congli psichiatri (in press)
10. Overall JE, Klett CJ: Applied Multivariate Analysis. New York, McGraw-Hill, 1972 Il. Overall JE: Historical and sociocultural factors related to the phenomenology of schizophrenia, in Siva Sankar DV (ed): Schizophrenia: Current Concepts and Research. Hicksville, N.Y., PJD Publications, 1968