Childhood Disintegrative Disorder: Results of the DSM-IV Autism Field Trial

Childhood Disintegrative Disorder: Results of the DSM-IV Autism Field Trial FRED R. VOLKMAR, M.D.,

AND

MICHAEL RUTTER, M.D.

ABSTRACT Objective: This report is concerned with the classification of children in whom an "autistic-like" syndrome develops

after some years of normal development. In OSM-/V the term "childhood disintegrative disorder" (COD) is used to describe such cases. Method: Data collected as part of the international, multisite OSM-/V field trial for autism and related conditions were examined and cases that met OSM-/V criteria for COD were identified. Results: In 16 cases the clinician had given a COD diagnosis; in an additional 10 cases criteria for the condition were met even though this diagnosis was not given by the clinician rating the case. Conclusions: The available data suggest that COD cases can be differentiated from those with autism; these two groups appear to differ in important ways. The identification of cases of COD may be of particular importance for research. J. Am. Acad. ChildAdo/esc. Psychiatry, 1995, 34, 8: 1092-

1095. Key Words: childhood disintegrative disorder, Heller's syndrome.

Childhood disintegrative disorder (COD) is a disorder which, while new to DSM-IV (American Psychiatric Association [APA], 1994), has its origin in a report made nearly 90 years ago. Viennese special educator Theodor Heller (1908) described six children who had undergone a marked regression at age 3 to 4 years, after what had otherwise appeared to be essentially normal development; recovery usually was very limited (see also Heller, 1930). Over the years this condition has been occasionally noted in the literature, mostly in the form of case reports (see Volkmar, 1992), and has been variously termed dementia infantilis, Heller's syndrome, disintegrative psychosis or disintegrative disorder or, as most recently in ICO-I0 (World Health Organization [WHO], 1990) and DSM-IV (APA, 1994), childhood disintegrative disorder.

In the years since Heller's first description, nearly 100 case reports of the condition have appeared (Volkmar, 1992) and general guidelines to the diagnosis have been identified, e.g., onset of the condition after a fairly prolonged period of normal development and marked deterioration in multiple developmental areas accompanied by development of various "autistic-like" features. The requirement for a prolonged period of normal development, usually of 3 or more years, before the regression is consistent with the literature on this condition and also helps differentiate it from Rett's disorder, with which it might potentially be confused (Burd et al., 1989); in the latter condition, reported only in girls, the period of normal development is usually short, i.e., typically a matter of months (Tsai, 1992). Although included in the International Classification ofDiseases, 9th and 10th editions (WHO, 1990), this diagnosis was included neither in DSM-III(APA, 1980) nor DSM-III-R (APA, 1987). The presumption in DSM-III and DSM-III-R was that these relatively rare cases either exhibited a progressive neurological condition (i.e., a "childhood dementia") or were, at least in DSM-III terms, examples of childhood-onset pervasive developmental disorder (POD). In DSM-III-R these patients would generally be said to have autistic disorder. As part of the DSM-IV revision process, a review of this condition (Volkmar, 1992) was undertaken in

Accepted December 20, 1994. Dr. Volkmar is Harris Associate Professor of Child Psychiatry, Pediatrics, and P,ychology, Yale University, New Haven, CT Dr. Rutter is Professor of Psychiatry, Department ofChild and Adolescent Psychiatry, Institute ofPsycbiatly, University of London. The comments and suggestions of Catherine Lord, Ph.D., are gratefully acknowledged as are the effirts of the various raters and site coordinators who participated in the DSM-IV Field Trial fOr Autistic Disorder. The opinions and conclusionsexpressed here are those ofthe authors and not necessarily those ofthe DSM-IV Child and Adolescent Disorders Work Group nor the American Psychiatric Association. Reprint requests to Dr. Volkmar, P.o. Box 207900, New Haven, Cl' 06520-7900. 0890-8567/95/3408-1 092$03.00/0© 1995 by the American Academy of Child and Adolescent Psychiatry.

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C\)\) IN IJSM-IV

light of the inclusion of the condition within the POD class in ICO-lO (WHO, 1990). Several lines of data appeared to support the inclusion of this condition in DSM-IV (Kurita, 1988; Lord and Rutter, 1994; Volkmar and Cohen, 1989) as a POD. Review of the available literature suggested that, once established, the condition clearly resembled autism in its behavioral features. In contrast to the assumption that the condition was alwaysassociated with some specific neurological condition, review of the reported cases suggested that this was usually not the case (Corbett, 1987; Corbett et al., 1977; Volkmar, 1992; Wilson, 1974). Even when the cases reported in the past two decades were examined (Volkmar, 1992), some specific neuropathological process was only occasionally identified although, as in autism, seizure disorders sometimes developed after the syndrome was established. COD, as usually defined, differed from autism in the mode of its presentation-both in terms of the prolonged period of normal development and the very dramatic loss of skills associated with the condition. Because the condition, once established, has many behavioral similarities to autism, a second set of issues related to whether the condition differed in important ways from autism, e.g., in terms of course and outcome. The available information suggested that the condition appeared to have an even worse prognosis than autism in multiple respects (Volkmar and Cohen, 1989). Given the controversy surrounding the DSM-Ill-R definition of autistic disorder, a large, multisite field trial was undertaken to provide data relative to the definition of autism in DSM-IV (see Volkmar et al., 1994). As part of this field trial, data were also collected on diagnostic criteria used in ICO-10 for the diagnosis of COD. While the field trial was primarily concerned with autism, the results are of some interest because of the decision to include COD in DSM-IVand because of the definition chosen for this condition. In addition, the limited data available provide some evidence relative to the delineation of the condition apart from autism.

of autism, 240 with "autistic-like" conditions, and 283 with nonPOD disorders). A standard coding system had been used by each of the 125 raters which included basic demograpbic inf'H'lnation, the rater's clinical (i.e., clinician-assigned) diagnosis, and explicit ratings of diagnostic criteria derived from the various "official" diagnostic systems. These criteria included the draft criteria for COD provided in ICD-IO (WHO, 1990). Raters could indicate that a criterion did or did not apply, was inapplicable, or could not be rated. Information on the presence of communicative speech, residential and educational placement, and level of associated mental retardation was usually available. A subset of cases (131) was rated independently by at least rwo raters; in these instances one rating was randomly chosen for inclusion in the main database. Data were coded to protect patient and rater confidentiality. Procedures and features of the entire sample are described in detail by Volkmar er al. (1994). For the present study, the DSM-IV criteria tor CDD were evaluated in the field trial sample. The following criteria for the diagnosis of COD are described in DSM-IV (APA, 1994): (I) a child must have exhibited normal development for at least 24 months with age-appropriate communication, social, play, and adaptive skills; (2) the child experiences a clinically significant loss of previously acquired developmental skills in the areas of language, social skills, toileting skills, play, or motor abilities before age 10 years; (3) there is a concomitant development of abnormalities of functioning in at least two of the three areas of abnormality observed in autism (impaired social interaction, communication, and restricted or repetitive patterns of behavior or activities); and (4) the disorder is not better accounted for by another POD or by schizophrenia. This definition differs slightly from that used in ICD- I 0; the latter system also includes a general loss of interest in the environment as a diagnostic criterion and is somewhat more detailed and more operationalized than that used in DSM-Iv' In DSM-IV, for example, the implicit suggestion is that the abnormalities in behavioral functioning are of the type seen in autism, although in ICD-IO it is clear that the actual behavioral criteria for autism must be met. In both systems the major distinction from autism is both the age at onset of the condition and the pattern of onset, i.e., ofa marked regression that follows a prolonged period of normal development with the onset of various behaviors commonly seen in autism. Because the diagnostic criteria are otherwise conceptually the same in both systems (Volkmar et aI., 1994), it was possible to apply both DSM-IVand ICD-10 criteria for CDD to the field trial cases. The issue of at least some potential differences between the COD and autism cases (as defined either by clinical diagnosis or application of DSM-IV and ICD-IO diagnostic criteria) could be, at least in part, addressed. Because the most relevant comparisons here involve the validity of eDD apart from autism, information on only these rwo conditions is presented as they are diagnosed either by the clinician's overall best judgment (clinical diagnosis) or through the analysis of the ratings of diagnostic criteria.

RESULTS METHOD Data collected as part of the DSM-IV Field Trial for Autistic Disorder were reanalyzed for this study. As part of this field trial (Volkmar et al., 1994), information had been obtained from 21 sites on 977 children, adolescents, and adults with severe developmental disturbances (454 with clinician-assigned diagnoses

j. AM. ACAD. CHILD ADOLESC. PSYCHIATRY. 34:8. AUGUST 1995

Sixteen patients had been given a clinician-assigned diagnosis of COD, and 453 patients had a clinicianassigned diagnosis of autism. The 16 patients included 10 cases previously reported by Volkmar and Cohen (1989), which were rerated for the field trial; the other

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on C O D as such), it was possible to examine th ose data that were available regardi ng potential differences between C O D and autism . On th e basis of eithe r clinician-assigned or DSM-IV-generated diagno ses, patients with C O D were more likely to be mute (Fisher 's p < .00 1 and < .002, respectively) and to have IQ scores of less than 40 (X2 = 22.8 and 14.4 , respectively; df = 1 and p < .001 for both com parisons) . Similarly, relative to cases with autism, th ose with C O D were more likely to be in residentia l placement; this was tr ue for both clinician- assigned and DSM-IV-assigned diagnoses (Fisher's p < .001 in both comparisons). As expected, given the definiti on of the disorder, th e differences in apparent onset of th e two conditions were significant. Pote nt ial differences in diagnostic criteria were also examined. Patients with C OD, regardless of how diagnosed, exhibited significantly more "a utis tic sympto ms" than the autistic gro up. As wou ld be expected, given the histo ry of the d iagnostic concep t and curre nt criteria, all cases accorded a DSM -IV diagnosis of C O D had been rated as having at least 2 years of normal developm ent before th e onset of the condition. T he median age at onset was 36 months; th e latest age at onset in th is group was 70 months. Both th e DSMI V system, as applied here, and IC O- lO definiti on yielded th e same results. In the 10 cases assig ned the CO D d iagn osis by clinician rating (but not by the clinician as such), the clinician-assigned diagnoses had included autism, atypic al autism, or POD not otherwise specified. Of th e 26 cases assigned a C O D diagnosis by DSM-IV

cases were drawn from two sites familiar with this co nd ition. As noted above, the DSM-IV criteria are ambiguous on the actual number of criteria for autis m which mu st be met; accordingly th e convent ion was ado pted th at, con sistent with the criteria for auti sm in DSM -I V and ICO-lO, a total of at least six such criteria had to be exhibited. The DSM -IV criteria for CO O were applied and all 16 cases met these criteria. In ano ther 10 cases, drawn from five different sites, the criteria for COD in DSM-IV were met but th e case had not been given this diag nosis by a clinic ian , i.e., th e clinician's ratings of the diagnostic criteria were consistent with COD bu t the clinician had not th ou ght to give this diagn osis. Feature s of these cases, and th e cases with clinicia n- or DSM-IV-based diagnosis of autism, are presented in Ta ble 1. Cases with C O D assigned by clinicia n or by appl icatio n of DSM-IV criteria d id not differ significantly in sex ratio from those assigned a diag nosis of autistic d isord er either by th e clin ician (clinical diagnosis) or by strict application of DSM-IV diagnostic criteria; in both instances the comparisons fell just short of statistical significance, with a prepon derance of males in the COD group . T he patients with COD were significantly older than those in th e autistic gro up (t = 2.89, df= 378, P < .0 1 and t = 2.00, df = 433, P < .05 for the clinician - and DSM-IV-diag nosed gro ups, respectively). T he older age of the COO gro up reflec ts the incl usion

of the rerated cases or iginally repo rted by Volkma r and Cohen (1989). Alth ough only limited data were collected in th e field tr ial (which in any event was not primarily focused

TABLE 1 Features of Diag nostic Groups: C hildhood Di sintegrative Disorder (CD D) and Auti sm

DSM-IV-Assigned

Clinician-Assigned Diagnosis CDD

n (M /F) Age (yr) Mean SD Onset (rno) Mean SD IQ < 40 ( n) Mute (n) Residentia l placement (n )

1094

16

(16/0)

Diagnosis CDD

Autism

451

(370/81)

26

(2511)

Autism

409

14.4 6.7

9.0 7.1

11.8 6.5

9. 1 6.9

37.9 12.4 13 15

12.6 10.7 114 229

35.3 10.7 16 21

12.1 9.7 104 200

II

14

51

J.

(331178)

55

AM . ACAD. C H I LD ADOL ESC . PSYCHIATRY. 3 4 :8 . AUGUS T 19 9 5

CDD IN DSM-IV

criteria, 7 would have been given a diagnosis of infantile autism by DSM-III criteria and 22 would have been given a diagnosis of autistic disorder by DSM-III-R criteria. In a final series of analyses, the entire field trial sample was examined for cases that fell "just short" of achieving the CDD diagnosis using DSM-IV criteria; seven such cases were identified. In these cases there was some question about whether or not the first 2 years of development had been normal. In one case a child had indeed appeared to develop normally for 18 months and then had a marked regression; by definition this child was excluded from the DSM-IV diagnosis because of the time of the regression.

of the condition is very unusual as compared to classic autism (Harper and Williams, 1975; Volkmar et al., 1985)-and these and other data suggest important differences from autism, e,g., in their course and outcome (Volkmar, 1992). As noted previously, the outcome in CDD appears to be worse than that for autism, even when the latter condition is identified somewhat later than usual (Volkmar and Cohen, 1989). On the other hand, the behavioral similarity to autism, once CDD is established, suggests the potential importance of research on this condition for clarifYing mechanisms of pathogenesis of potential relevance to autism as well. REFERENCES

DISCUSSION

The data presented here are of interest in several respects. It was possible to identify cases of CDD using the DSM-IV criteria; this was true even when the clinician was apparently unaware of this diagnostic concept. Second, it appeared that there were indeed meaningful differences between autism and CDD regardless of whether these conditions were defined on the basis of clinician's diagnosis or DSM-IV criteria. Although good epidemiological data are lacking, it is undoubtedly true that CDD is much less frequent than autism (Volkmar, 1992). It also seems likely, given the present data, that the condition may have been incorrectly diagnosed in the past. The observation that some clinicians failed to assign a clinical diagnosis of CDD likely reflects the lack of familiarity with this condition (which had not previously been included in DSM) as well as its true infrequency (Volkmar, 1992). This observation would appear to strengthen the case for inclusion of the category in DSM-IV, since it was possible to identify such cases on the basis of diagnostic criteria even when the clinician was not familiar with the diagnosis. As noted elsewhere (e.g., Lord and Rutter, 1994; Volkmar, 1992), CDD is of interest not because of its frequency, but because of the possible implications for research. In general, the attempt to describe specific "subgroups" or "subtypes" of autism has not provided particularly robust subgroups for research purposes. CDD may be an exception in that the pattern of onset

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American Psychiatric Association (1980), Diagnosticand Statistical Manual ofMental Disorders, 3rd edition (DSM-ffl). Washington, DC: American Psychiatric Association American Psychiatric Association (1987), Diagnosticand Statistical Manual ofMental Disorders, 3rd edition-revised(DSM-Iff-R). Washington, DC: American Psychiatric Association American Psychiatric Association (1994), Diagnosticand Statistical Manual ofMental Disorders, 4th edition (DSM-IV). Washington, DC: American Psychiatric Association Burd L, Fisher W, Kcrbeshian J (1989), Pervasive disintegrative disorder: are Rett syndrome and Heller dementia infantilis subtypes? Deu Med Child Neural 31 :609-616 Corbett J (1987), Development, disintegration and dementia. J Ment Deftc Res 31 :349-356 Corbett J, Harris R, Taylor E ct a!. (1977), Progressive disintegrative pyschosis of childhood. J Child Psychol Psychiatry 18:211-219 Harper J, Williams S (1975), Age and type of onset as critical variables in early infantile autism. J Autism Child Schizophr 5:25-35 Heller T (1908), Dementia infantilis. Zeitschrift [ur die ErJOrschung und Bebandlung des[ugenlicben Schwachsinns 2: 141-165 Heller 'I (1930), Ubcr dementia infantalis. Zeitschrift [ur Kinderforschung 37:661-667 (Reprinted in Modern Perspective in International Child Psychiatry, Howells JG, cd. New York: Bruner/Mazel, pp 610-616) Kurita H (1988), The concept and nosology of Heller's syndrome: review of articles and repott of rwo cases. [pn J Psychiatry NeuroI42:785-793 Lord C, Rutter M (1994), Autism and pervasive developmental disorders. In: Child and AdolescentPsychiatry: Modern Approaches, 3rd ed., Rutter M, Taylor E, Hersov L, cds., Oxford: Blackwell, pp 569-593 Tsai L (1992), Is Rett syndrome a subtype of pervasive developmental disorder? J Autism Dev Disord 22:551-561 Volkmar FR (1992), Childhood disintegrative disorder: issues for DSM-

IV.

J Autism Dev Disord 22:625-642

Volkmar FR, Cohen OJ (1989), Disintegrative disorder or "late onset" autism. J Child Psycho! Psychiatry 30:717-724 Volkmar FR, Klin A, Siegel Bet a!. (1994), Field trial for autistic disorder in DSM-IV. Am J Psychiatry 151:1361-1.167 Volkmar FR, Stier DM, Cohen DJ (1985), Age of recognition of pervasive developmental disorder. Am J Psychiatry 142:1450-1452 Wilson J (1974), Investigation of degenerative disease of the central nervous system. Arch Dis Child 47:163-170 World Health Organization (1990), International Classification of Diseases (Draft Version: DiagnosticCriteriafor Research), l Oth cd. Geneva: World Health Organization

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