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Information processing deficits of schizophrenic children with formal thought disorder
Psychiatry Resmrch. 3 I : I69-
169
I77
Elsevier
Information Processing Children With Formal Rochelle Receivrd 1989.
Caplan,
Judith
Deficits Thought
G. Foy, Robert
of Schizophrenic Disorder F. Asarnow,
April IS, 1989; revised version received Novemhr
and Tracy
Sherman
17. 1989; acceppled December 31,
Abstract. The relations among formal thought disorder, the partial report span of apprehension task, the distractibility factor on the Wechsler Intelligence Scale for Children-Revised (WISC-R), and IQ scores were examined in 31 schizophrenic children, aged 7.4 to 12.5 years. The partial report span of apprehension scores of the schizophrenic children correlated significantly with their illogical thinking scores. Their scores on loose associations were significantly associated with the WISC-R distractibility factor score. The attention/information processing deficits that might underlie the clinical manifestations of illogical thinking and loose associations in childhood onset schizophrenia are discussed.
Key Words. Schizophrenia, distractibility, Formal
thought
formal thought span of apprehension task.
disorder
(FTD)
is a DSM-III
disorder,
(American
information
processing,
Psychiatric
Association,
signs: illogical thinking, loose associations, incoherence, and poverty of content of speech. Due to the lack of developmental norms for rating FTD in middle childhood and difficulties in obtaining adequate speech samples from children, Caplan et al. (1989~) examined whether these FTD signs could be reliably used in children. They operationalized the four DSM-//I FTD criteria for use with children and developed the Kiddie Formal Thought Disorder Scale (K-FTDS). The definitions for the K-FTDS signs were based on Andreasen’s (1979) Thought, Language, and Communication Scale, the Research Diagnostic Criteria (RDC; Spitzer et al., 1973, and studies of normal children’s conversation skills (Ochs and Schieffelin, 1979; Romaine, 1984). The Kiddie Formal Thought Disorder Story Game, designed to obtain adequate speech samples from children, was modified after Gardner’s (1971) clinical instrument for therapeutic communication with children. Two of the four K-FTDS signs, illogical thinking and loose associations, were reliable and valid measures in a mixed group of I6 schizophrenic and 4 schizotypal 1980)
inclusionary
criterion
of
schizophrenia
and
includes
four
Rochelle Caplan, M.D.. is Assistant Professor. Division of Child Psychiatry, Neuropsychiatric Institute. IJCLA, Los Angeles, CA. Judith G. Foy, Ph.D., was Postdoctoral Fellow, Division of Child Psychiatry, Neuropsychiatric Institute, UCLA, and is currently affiliated with the Department of Psychology, Loyola Marymount University, Los Angeles, CA. Robert F. Asarnow. Ph.D., is Associate Professor, Division of Child Psychiatry, Neuropsychiatric Institute, UCLA, Los Angeles. CA. Tracy Sherman, Ph.D.. is with Research Design and Analysis Consultants, Bethesda, MD. (Reprints requests to Dr. R. Caplan, Neuropsychiatric Institute, 760 Westwood Plaza. Los Angeles, CA 90024, USA.) Ol65-1781/90/$03.50
@ 1990 Elsevier Scientific Publishers Ireland Ltd
170 children and their normal chronological age matches and mental age matches (Caplan et al., 1989~). Loose associations correctly classified 91% of the normal children and were found specifically in the schizophrenic and schizotypal children (Caplan et al., 1989~). The remaining two K-FTDS signs, incoherence and poverty of content of speech, were coded infrequently in this sample. Loose associations are rated when the child unpredictably changes the topic of conversation without preparing the listener for the topic change (Caplan et al., 1989~). Attention abilities, but not memory and IQ, per se, appear to play an important role in the young child’s inability to monitor his or her verbal communication (Asher, 1979; Flavell et al., 1981; Saywitz and Wilkinson, 1982). We therefore hypothesized that loose associations might reflect the attentional impairment found in schizophrenic children (Asarnow and Sherman, 1984; Asarnow et al., 1986, 1987). Numerous studies indicate that adults with schizophrenia and schizotypy appear to have impaired attention/ information processing abilities (Asarnow and MacCrimmon, 1978, 1981; Oltmanns, 1978; Walker, 1981; Gjerde, 1983; Nuechterlein and Dawson, 1984; Saccuzzo and Braff, 1986) and mild global cognitive deficits (see review in Chapman and Chapman, 1973). Few studies, however, have specifically explored the relationship between the clinical manifestations of FTD and cognitive processes in adult schizophrenic patients (Oltmanns et al., 1979; Neale et al., 1985; Nuechterlein et al., 1986; Harvey et al., 1988). Although studied in children at risk for schizophrenia (Cornblatt and ErlenmeyerKimling, 1985), the relationships among thought disorder, information processing deficits,, and global cognitive dysfunction have not been examined in childhood onset schizophrenia. Information processing skills in schizophrenic children have been found to be significantly lower as compared to younger mental-age-matched normal children on the basis of scores on a partial report span of apprehension task (Asarnow and Sherman, 1984). Asarnow and Sherman (1984) hypothesized that schizophrenic children, like adult schizophrenic patients, have a core deficit in their ability to recruit and allocate information processing capacity for controlled 1985). The significantly lower attentional processes (Sherman and Asarnow, “freedom from distraction” factor scores on the Wechsler Intelligence Scale for Children-Revised (WISC-R; Kaufman, 1979) of these children compared to chronological-age-matched autistic children could also reflect their reduced processing capacity (Asarnow et al., 1987). Regarding the relationship between global cognitive deficits and FTD, we recently found that loose associations, but not illogical thinking, were associated with full scale and verbal IQ scores in a combined group of schizophrenic and schizotypal children (Caplan et al., 19896). The goal of this study was to examine whether loose associations represent a clinical manifestation of impaired attention/information processing, as well as of global cognitive deficits in schizophrenic children. We predicted that the scores of schizophrenic children on loose associations would be associated with WISC-R distractibility factor scores and performance on the partial report span of apprehension task, as well as with full scale and verbal IQ measures.
171
Methods This study was conducted on 3 I (25 male and 6 female) schizophrenic subjects, with a mean chronological age of 10.2 (SD = 1.5) years and mental age of 9.1 (SD = 2.0) years (Table I). The schizophrenic subjects were recruited from the UCLA Neuropsychiatric Institute’s Inpatient and Outpatient Child Services, as well as from two Los Angeles schools for the emotionally disturbed. They were diagnosed independent of the research team by the Diagnostic Unit of UCLA’s Childhood Psychoses Clinical Research Center with the Interview for Childhood Disorders and Schizophrenia (ICDS; Russell et al., 1989). The reliability of the ICDS (kappa = 0.89) was determined on 23 cases (Russell et al., 1989). This interview includes questions that ensure an adequate assessment of schizophrenia and schizotypal personality disorder in children. It was derived from the Schedule for Affective Disorders and Schizophrenia for School-Age Children (Kiddie-SADS; Puig-Antich and Chambers, 1978) and the Diagnostic Interview for Children and Adolescents (DICA; Herjanic and Campbell, 1977). At the time of testing, 70% of the schizophrenic children were inpatients and 50% were on neuroleptic medication. The remaining children had not received neuroleptics for at least 2 weeks before their participation in the study. Children with a neurological, language, or hearing disorder were excluded from the study. The Kiddie Formal Thought
Disorder Story Game. A trained clinician administered the Story Game’s three parts (Caplan et al., 1989a). In the first and last part, the child heard an audiotaped story, retold the tale, and was asked standardized questions on each story. In the second part of the Story Game, the child was asked to make up a story chosen from four topics. The topics of all the stories were chosen because of their potential for eliciting pathological thought content in children. It was hoped that while the psychotic child was actively engaged in pathological thinking, the nonthreatening and indirect interview technique used in the Story Game would allow the child to be more expansive and reveal more FTD in his or her speech.
The Kiddie Formal Thought
Disorder Rating Scale (K-FTDS). Videotapes of the 20- to 2%min Story Game were rated with the K-FTDS by two trained raters who had no previous knowledge of the individual’s child’s diagnosis (Caplan et al., 1989~). The following synopsis presents an outline of the definitions of the K-FTDS signs. Illogical thinking was evaluated in three conditions. In the first condition, the child used causal utterances inappropriately. For example, “I left my hat in her office because her name is Mary.” In the second condition, the child presented the listener with unfounded and inappropriate reasoning in noncausal utterances. For example, “Sometimes I’ll go to bed and when I’m done laughing, I start wheezing and that’s when I relax.” In the third condition, the child contradicted himself or herself within one to two utterances by simultaneously making and refuting statements. For example, “I don’t like that story, but I liked it.” Ratings of loose associations were made when the child made an utterance that was offtopic without having previously prepared the listener for the topic change. For example: (Interviewer) “Why do you think that’s a reason not to like Tim?“(Child) “And I call my mom sweetie.” An utterance was rated as incoherence if the rater could not comprehend its contents because of scrambled syntax. For example: (Interviewer) “What happened next in your story?” (Child) “The day no witches no day goes.” Poverty of content of speech was rated if, in the presence of at least two utterances, the child did not elaborate on the topic of conversation. For example: “I suppose . . What? Maybe _.. Well, yes, I see. I suppose that’s all.” The scores derived from these ratings were frequency counts of illogical thinking, loose
172 associations, incoherence, and poverty of content of speech divided by the utterances during a 5-min sample of the Story Game. Due to the low base rate of and poverty of content of speech, they were not included in subsequent analyses. corrected kappa reliability statistic (Fleiss, 1973) was 0.78 and 0.71, respectively, thinking and loose associations (Caplan et al., 1989~).
number of incoherence The chancefor illogical
Table 1. Cognitive parameters, formal thought disorder scores, and medication status of the schizoohrenic children All children (n = 31) Data Mental age Chronological
age
Children with Span (n = 19)
Mean
SD
Mean
SD
9.3 10.3
2.00
9.7
2.00
1.51
10.4
1.5
Full scale IQ (WISC-R)
90
12.37
93
10.3
Verbal
88
16.31
94
12.2
93
16.27
95
14.7
IQ
Performance
IQ
7.1
2.19
7.3
2.08
Illogical thinking
0.33
0.29
0.23’
0.18
Loose associations
0.13
0.17
0.11
0.12
WISC-R
distractibility
factor score
Medication status On
16
NA
10
NA
Off
15
NA
9
NA
Note. Span = span of apprehension task. WISC-R z Wechsler lntelllgence
Scale for Children-Revised
1. The t test (t = 1.34, df = 48) was almost significant at the 0.1 level
The Wechsler Intelligence Scale for Children-Revised (WISC-R). The WISC-K was administered to all children by a psychometrist who was aware of the children’s diagnosis. The verbal comprehension (factor I), perceptual organization (factor 2), and distractibility (factor 3) WISC-R factor scores were derived from the WISC-R subscales according to Kaufman ( 1979). The Span of Apprehension. A subsample of I6 male and 3 female schirophrenic children were available to participate in the partial report span of apprehension task. These subjects had a mean chronological age, mental age, and full scale IQ of 10.4 (SD = I .47) years. 9.7 (SD = 1.99) years, and 93 (SD = 10.3), respectively (Table I). The span of apprehension task provides an index of the rate of visual information processing and is described in detail in Asarnow and MacCrimmon ( 1978, I9X I ). Data Analysis. We obtained FTD, WISC-R factor, and IQ scores on all 3 I schirophrenic children and span of apprehension data on I9 of the children. The relationships among the K-FTDS, WISC-R factor, IQ, and span of apprehension scores were computed using Pearson pairwise correlations. Due to the effects of age on the K-FTDS (Caplan et al., 19x9~) and span of apprehension scores (Asarnow and Sherman, 19X4), we partialled out chronological age from these correlations. We present only the partial correlations.
Results K-FTDS, (Table
2):
significantly
WISC-R Factor, and IQ Scores. We found the following relationships (I) Illogical thinking (ILL) and loose associations (LA) were not correlated
(rtt,t*,~~
= -0. I I, p <
0.5). (2) Loose
associations
were
173 negatively and significantly correlated with full scale IQ (~LA/FSIQ = -0.43, < 0.01) and the WISC-R distractibility factor (rLA/Fa&r 3 = -0.43, p < 0.02) but not with the verbal IQ (rLA,viQ = -0.26, p < 0.2) and performance IQ subscores (rLA,PiQ = -0.36, p < 0.05).(3) Illogical thinking was not significantly associated with full scale IQ (~ILL/FSIQ = 0.18, p < 0.4) verbal IQ (TILL/VIQ = 0.05, p < 0.7) performance IQ (rlLL/PlQ = 0.16, p < 0.3) or the distractibility factor scores nor illogical thinking (r ILL/ Factor 3 = 0.20, p < 0.3). (4) Neither loose associations was associated with the perceptual organization (rLA/Fa&r 2 = -0.29, p < 0.2; factor scores (rLA, Factor 1 = r ILL/ Factor 2 = 0.06, p < 0.7) or verbal comprehension -0.22, p < 0.2; rlLLIFactor 1 = 0.00&p < 0.9). The WISC-R distractibility factor score is composed of one verbal subscale, arithmetic, and three performance subscales, digit span, coding, and mazes. We therefore examined if the significant associations between loose associations and full scale IQ, and between loose associations and performance IQ, were primarily due to the distractibility factor subscales. After partialling out the variance from the distractibility factor scores, we found that loose associations were no longer significantly correlated with fullscale IQ (rLA/FS[Q = -0.29, p < 0.2) and performance IQ (~LA/PIQ = 0.09, p < 0.6). There was no change in the loose associations/verbal IQ association (~LA/VIQ = - 0.25, p < 0.2).
p
of Apprehension, K-FTDS, and WISC-R Factor Scores. The schizophrenic children with lower partial report span of apprehension scores had higher illogical thinking scores (rs pan,l~t =-0.42,p
Table 2. Correlation1 between K-FTDS, span of apprehension*, factor, and IQ scores in schizophrenic children Illogical Cognitive
measures
Span
thinking -0.42’
Loose associations
Span of apprehension
0.23
Factor
1
0.002
-0.21
-0.22
Factor
2
0.13
-0.29
0.28
Factor
3
0.20
-0.432
0.18
0.18
-0.434
0.15
0.05
-0.29
0.19
0.16
-0.36
0.13
-0.41 3
-0.372
0.24
Full
scale
Verbal
IQ
IQ
Performance Chronological
IQ age
WISC-R
Note. With the exceptron of the chronological age correlations, the correlations measures are presented after partialltng out chronological age. The correlations with the span of apprehension (Span) were computed on a subsample of 19 schizophrenic children. The remaining correlations were calculated for the 31 schizophrenic children. K-FTDS = Kiddie Formal Thought Disorder Story Game. WISC-R = Wechsler Intelligence Scale for Children-Revised. 1. p < 0.05 (remains significant after partialltng out the distractibrlity factor). 2. p < 0.02. 3. p < 0.01. 4. p < 0.01 (no longer significant after partialling out the distractibility factor score).
174 (‘Span/LA = 0.23, p < 0.3). The span of apprehension the schizophrenic children’s IQ measures and WISC-R
scores were also unrelated factor scores.
to
K-FTDS, Cognition, and Neuroleptic Medication. We investigated the effects of the medication status of the schizophrenic children on their FTD, WISC-R factor, IQ, and span of apprehension scores using t tests. There were no significant differences in the illogical thinking (t = 0.25, df = 29,~ > 0.2) span of apprehension (t = I .02, df = 17, p > 0.3), and WISC-R factor scores (t ~~~~~~1 = 0.2 I, df = 29, p > 0.2; t ~~~~~~2 = 0.12, df = 29, p > 0.2; t Factor 3 = 0.12, df = 25, p > 0.2) of the medicated and unmedicated subjects. Although the schizophrenic children on medication tended to have lower scores on loose associations than the unmedicated children, this difference was not significant (t = I .5, n = 29, p < 0.2). Discussion The results of this study suggest that loose associations and illogical thinking could represent different aspects of attention processing in schizophrenic children for the following reasons: (I) These two FTD signs were not correlated with each other and therefore appear to be independent clinical manifestations of FTD. (2) Each of the two K-FTDS signs had different cognitive correlates. Illogical thinking appears to be related to a deficit in momentary processing capacity, measured by the partial report span of apprehension task. Loose associations, however, appear to reflect “distractibility,” as indicated by a correlation with the WISC-R distractibility factor score. What is the possible clinical relevance of the significant associations between illogical thinking and the span of apprehension, and between loose associations and distractibility? The child with illogical thinking presents the listener with inappropriate reasoning. It is possible that the requirement to present the listener with logical reasoning taxes the schizophrenic child’s momentary processing capacity. In contrast, the child with loose associations unpredictably changes the topic of conversation without preparing the listener for the topic change. The cognitive demands of this situation could reflect distractibility more than reduced momentary processing capacity. Similar findings in adults lend credence to the major findings of this study. Converging with the first set of findings, Andreasen and Grove (1986) have suggested that in schizophrenic adults negative FTD signs, such as illogical thinking and poverty of content of speech, reflect the patients’ difficulty generating conversation. Nuechterlein et al. (1986) demonstrated that negative signs of schizophrenia were associated with impaired performance on the continuous performance test and the span of apprehension task that could have reflected processing overload. In support of our second set of findings, several studies reported a relationship between positive symptoms of schizophrenia, such as loose associations and distractibility, in adult schizophrenic patients (Cornblatt et al., 1985; Harvey et al., 1986, 1988; Oltmanns et al., 1979). Our findings that illogical thinking and loose associations reflect different aspects of attention/information processing in schizophrenic children, therefore, appear to be similar to those in schizophrenic adults.
175 There are two possible concerns about the generalizability of these findings. The first concern is the lower illogical thinking scores of the subsample for whom span of apprehension scores were available compared to those of the entire sample. It is unlikely, however, that reducing the range of illogical thinking scores would result in an increased illogical thinking/ span of apprehension correlation. The second concern is the tendency of neuroleptic medication to reduce the loose associations scores of the schizophrenic children. It is possible that this restricted range of loose associations scores could have affected the correlation with the span of apprehension scores. We are currently conducting a study to examine the effects of neuroleptic medication on the K-FTDS and span of apprehension measures in a larger sample of children. Our prediction that loose associations would also be associated with global cognitive dysfunction was based on our recent findings that schizophrenic and schizotypal children with higher loose associations scores had lower full scale and verbal IQ scores (Caplan et al., 1989b). By beginning to tease out the cognitive/ information processing correlates of this FTD sign in the study presented in this article, we have demonstrated that this FTD sign reflects specific attentional impairment and not global cognitive dysfunction. In conclusion, this is the first study to examine the relations among clinical measures of FTD, global measures of cognitive functioning (IQ), and specific measures of attention/information processing (WISC-R distractibility factor and span of apprehension) in schizophrenic children. We found an orderly set of correlations suggesting that individual are associated with specific attentional
symptoms processing
of FTD in schizophrenic capacities.
children
Acknowledgment. This study was supported by National Institute of Mental Health grants KOI-MH-00538 (R.C.), MH-16381 (J.G.F. and T.L.S.), and MacArthur Foundation grant MH-30897 (R.F.A.). Additional support was provided by grant MH-30897 from the National Institute of Mental Health to the UCLA Childhood Psychoses Clinical Research Center and by the UCLA Women’s Hospital Auxiliary. Technical assistance was given by Anne Brothers, Amy MO, Diane Putney, R.N., Diane Greene, and Chenga Buanausi. Sondra Perdue, Dr. M.P.H., also provided statistical consultation.
References American Psychiatric Association. DSM-III: Diagnostic and Statistical Manual of Mental Disorders. 3rd ed. Washington, DC: APA, 1980. Andreasen, N.C. Thought, language, and communication disorders: I. Clinical assessment, definition of terms, and evaluation of their reliability. Archives of General fqwhiatry. 36:1315-1323, 1979. Andreasen, N.C., and Grove, W.M. Thought, language, and communication in schizophrenia: Diagnosis and prognosis. Schizophrenia Bulletin, I2:348-359, 1986. Asarnow, R.F., and MacCrimmon, D.J. Residual performance deficit in clinically remitted schizophrenics: A marker of schizophrenia? Journal qf Abnormal Psychology, 87597-608, 1978. Asarnow, R.F., and MacCrimmon, D.J. Span of apprehension deficits during postpsychotic stages of schizophrenia: A replication and extension. Archives of’ General Psychiatry. 38: IO0 I - 1006, I98 I
176
Asarnow, R.F., and Sherman, T. Studies of visual information processing in schizophrenic children. Child Development. 55:249-26 I, 1984. Asarnow, R.F.; Sherman, T.L.; and Strandburg, R. The search for the psychobiological substrate of childhood onset schizophrenia. Journal of the American Academy of Child Psvc’hiatry. 26:60 I-604, 1986. Asarnow, R.F.; Tanguay, P.E.; Bott, L.; and Freeman, B.J. Patterns of intellectual functioning in non-retarded autistic and schizophrenic children. Journalof Child Pqx~holugy and P.y_vchiatr,v, 26:273-280, 1987. Asher, S.R. Referential communication. In: Whitehurst, G.J., and Zimmerman, B.J., eds. The Functions of Language. New York: Academic Press, 1979. pp. 175-197. Caplan, R.; Guthrie, D.; Fish, B.; Tanguay, P.E.; and David-Lando, G. The Kiddie Formal Thought Disorder Scale (K-FTDS): Clinical assessment, reliability, and validity. Journal of the American Academy of’ Child Psychiatry. 28:408-4 16, I989a. Caplan, R.; Perdue, S.; Tanguay, P.E.; and Fish, B. Formal thought disorder in childhood onset schizophrenia and schizotypal personality disorder. Submitted for publication, 19896. Chapman, L.J., and Chapman, J.P. Disordered Thought in Schizophrenia. Englewood Cliffs, NJ: Prentice-Hall, 1973. Cornblatt, B., and Erlenmeyer-Kimling, L. Global attentional deviance in children at risk for schizophrenia: Specificity and predictive validity. Journal of’ Abnormal Ps_vcholog_v, I I :397-408, 1985. Cornblatt, B.A.; Lenzenweger, M.F.; Dworkin, R.H.; and Erlenmeyer-Kimling, L. Positive and negative schizophrenic symptoms, attention, and information processing. Schizophrenia Bulletin, I I :397-408, 1985. Flavell, J.H.; Speer. J.R.; Green, F.L.; and August, D.L. The development of comprehension monitoring and knowledge about communication. Monographs ofthe Societ.r fbr Research in Child Development. 46(5): Serial No. 192, I98 I Fleiss, J. Statistical Methods.for Rates and Proportions. New York: John Wiley 8~ Sons, 1973. Gardner, R.A. Therapeutic, Communication With Children: The Mutual Storvtelling Technique. New York: Science House, Inc., 1971. Gjerde, P.F. Attentional capacity dysfunction and arousal in schizophrenia. Psychological Bulletin, 93157-72, 1983. Harvey, P.D.; Earle-Boyer, E.A.; and Levinson, J.C. Distractibility and discourse failure: Their association in mania and schizophrenia. Journal of’ Nervous and Mental Disease, 174~274-279, 1986. Harvey, P.D.; Earle-Boyer, E.A.; and Levinson, J.C. Cognitive deficits and thought disorder: A retest study. Schizophrenia Bulletin, 14:57-66, 1988. Herjanic, B., and Campbell, W. Differentiating psychiatrically disturbed children on the basis of a structured interview. Journal of Abnormal Child P.~_yc.hology,5: 127-134, 1977. Kaufman, A.S. Intelligence Testing With the WISC-R. New York: Wiley, 1979. Neale, J. M.; Oltmanns, T.F.; and Harvey, P.D. The need to relate cognitive deficits to specific behavioral referents of schizophrenia. Schizophrenia Bulletin. I I : 186-29 I, 1985. Nuechterlein. K.H., and Dawson, M.E. Information processing and attentional functioning in the developmental course of schizophrenic disorders. Schizophrenia Bulletin, IO: 160-202, 1984. Nuechterlein, K.H.; Edell, W.S.; Norris, M.; and Dawson, M.E. Attentional vulnerability indicators, thought disorder, and negative symptoms. Schizophrenia Bulletin. 12:408-426. 1986. Ochs, E., and Schieffelin, B.B. Developmental Pragmatics. New York: Academic Press, 1979. Oltmanns, T.F. Selective attention in schizophrenic and manic psychoses: The effect of distraction on information processing. Journal qf Abnormal P.~_ychdo~y, X7:2 12-225, 1978.
177 Oltmannns, T.F.; Ohayon, J.; and Neale, J.M. The effect of antipsychotic medication and diagnostic criteria on distractibility in schizophrenia. Journal c$ Psychiatric Research, 14:8191, 1979. Puig-Antich, J., and Chambers W. The Schedule.for Affective Disorders and Schizophrenia for School-Age Children (KiddieSADS). New York: New York State Psychiatric Institute, 1978. Romaine, S. The Language of Children and Adolescents. New York: Basil Blackwell, 1984. Russell, A.T.; Bott, L.; and Sammons, C. The phenomenology of schizophrenia occurring in childhood. Journal of the American Academy of Child Psychiatry, 28:399-407, 1989. Saccuzzo, D.P., and Braff, D.L. Information processing abnormalities: Trait- and statedependent components. Schizophrenia Bulletin, 12:446-459, 1986. Saywitz, K., and Wilkinson L.C. Age related differences in metalinguistic awareness. In: Kuczaj, S.A. II, ed. Language Development. Vol. 2. Hillsdale, NJ: Lawrence Erlbaum Associates, 1982. pp. 229-250. Sherman, T., and Asarnow, R.F.The cognitive disabilities of the schizophrenic child. In: Sigman, M., ed. Children With Emotional Disorders and Developmental Disabilities: Assessment and Treatment. Orlando, FL: Grune and Stratton, Inc., 1985. pp. 153-170. Spitzer, R.L.; Endicott, J.; and Robins, E. Research Diagnostic Criteria (RDC)Jor a Selected Group of Functional Disorders. 2nd ed. New York: New York State Psychiatric Institute, 1975. Walker, E. Attentional and neuromotor functions of schizophrenics, schizoaffectives, and patients with other affective disorders. Archives of General Psychiatry. 38: 1355-l 358, 1981.
169
I77
Elsevier
Information Processing Children With Formal Rochelle Receivrd 1989.
Caplan,
Judith
Deficits Thought
G. Foy, Robert
of Schizophrenic Disorder F. Asarnow,
April IS, 1989; revised version received Novemhr
and Tracy
Sherman
17. 1989; acceppled December 31,
Abstract. The relations among formal thought disorder, the partial report span of apprehension task, the distractibility factor on the Wechsler Intelligence Scale for Children-Revised (WISC-R), and IQ scores were examined in 31 schizophrenic children, aged 7.4 to 12.5 years. The partial report span of apprehension scores of the schizophrenic children correlated significantly with their illogical thinking scores. Their scores on loose associations were significantly associated with the WISC-R distractibility factor score. The attention/information processing deficits that might underlie the clinical manifestations of illogical thinking and loose associations in childhood onset schizophrenia are discussed.
Key Words. Schizophrenia, distractibility, Formal
thought
formal thought span of apprehension task.
disorder
(FTD)
is a DSM-III
disorder,
(American
information
processing,
Psychiatric
Association,
signs: illogical thinking, loose associations, incoherence, and poverty of content of speech. Due to the lack of developmental norms for rating FTD in middle childhood and difficulties in obtaining adequate speech samples from children, Caplan et al. (1989~) examined whether these FTD signs could be reliably used in children. They operationalized the four DSM-//I FTD criteria for use with children and developed the Kiddie Formal Thought Disorder Scale (K-FTDS). The definitions for the K-FTDS signs were based on Andreasen’s (1979) Thought, Language, and Communication Scale, the Research Diagnostic Criteria (RDC; Spitzer et al., 1973, and studies of normal children’s conversation skills (Ochs and Schieffelin, 1979; Romaine, 1984). The Kiddie Formal Thought Disorder Story Game, designed to obtain adequate speech samples from children, was modified after Gardner’s (1971) clinical instrument for therapeutic communication with children. Two of the four K-FTDS signs, illogical thinking and loose associations, were reliable and valid measures in a mixed group of I6 schizophrenic and 4 schizotypal 1980)
inclusionary
criterion
of
schizophrenia
and
includes
four
Rochelle Caplan, M.D.. is Assistant Professor. Division of Child Psychiatry, Neuropsychiatric Institute. IJCLA, Los Angeles, CA. Judith G. Foy, Ph.D., was Postdoctoral Fellow, Division of Child Psychiatry, Neuropsychiatric Institute, UCLA, and is currently affiliated with the Department of Psychology, Loyola Marymount University, Los Angeles, CA. Robert F. Asarnow. Ph.D., is Associate Professor, Division of Child Psychiatry, Neuropsychiatric Institute, UCLA, Los Angeles. CA. Tracy Sherman, Ph.D.. is with Research Design and Analysis Consultants, Bethesda, MD. (Reprints requests to Dr. R. Caplan, Neuropsychiatric Institute, 760 Westwood Plaza. Los Angeles, CA 90024, USA.) Ol65-1781/90/$03.50
@ 1990 Elsevier Scientific Publishers Ireland Ltd
170 children and their normal chronological age matches and mental age matches (Caplan et al., 1989~). Loose associations correctly classified 91% of the normal children and were found specifically in the schizophrenic and schizotypal children (Caplan et al., 1989~). The remaining two K-FTDS signs, incoherence and poverty of content of speech, were coded infrequently in this sample. Loose associations are rated when the child unpredictably changes the topic of conversation without preparing the listener for the topic change (Caplan et al., 1989~). Attention abilities, but not memory and IQ, per se, appear to play an important role in the young child’s inability to monitor his or her verbal communication (Asher, 1979; Flavell et al., 1981; Saywitz and Wilkinson, 1982). We therefore hypothesized that loose associations might reflect the attentional impairment found in schizophrenic children (Asarnow and Sherman, 1984; Asarnow et al., 1986, 1987). Numerous studies indicate that adults with schizophrenia and schizotypy appear to have impaired attention/ information processing abilities (Asarnow and MacCrimmon, 1978, 1981; Oltmanns, 1978; Walker, 1981; Gjerde, 1983; Nuechterlein and Dawson, 1984; Saccuzzo and Braff, 1986) and mild global cognitive deficits (see review in Chapman and Chapman, 1973). Few studies, however, have specifically explored the relationship between the clinical manifestations of FTD and cognitive processes in adult schizophrenic patients (Oltmanns et al., 1979; Neale et al., 1985; Nuechterlein et al., 1986; Harvey et al., 1988). Although studied in children at risk for schizophrenia (Cornblatt and ErlenmeyerKimling, 1985), the relationships among thought disorder, information processing deficits,, and global cognitive dysfunction have not been examined in childhood onset schizophrenia. Information processing skills in schizophrenic children have been found to be significantly lower as compared to younger mental-age-matched normal children on the basis of scores on a partial report span of apprehension task (Asarnow and Sherman, 1984). Asarnow and Sherman (1984) hypothesized that schizophrenic children, like adult schizophrenic patients, have a core deficit in their ability to recruit and allocate information processing capacity for controlled 1985). The significantly lower attentional processes (Sherman and Asarnow, “freedom from distraction” factor scores on the Wechsler Intelligence Scale for Children-Revised (WISC-R; Kaufman, 1979) of these children compared to chronological-age-matched autistic children could also reflect their reduced processing capacity (Asarnow et al., 1987). Regarding the relationship between global cognitive deficits and FTD, we recently found that loose associations, but not illogical thinking, were associated with full scale and verbal IQ scores in a combined group of schizophrenic and schizotypal children (Caplan et al., 19896). The goal of this study was to examine whether loose associations represent a clinical manifestation of impaired attention/information processing, as well as of global cognitive deficits in schizophrenic children. We predicted that the scores of schizophrenic children on loose associations would be associated with WISC-R distractibility factor scores and performance on the partial report span of apprehension task, as well as with full scale and verbal IQ measures.
171
Methods This study was conducted on 3 I (25 male and 6 female) schizophrenic subjects, with a mean chronological age of 10.2 (SD = 1.5) years and mental age of 9.1 (SD = 2.0) years (Table I). The schizophrenic subjects were recruited from the UCLA Neuropsychiatric Institute’s Inpatient and Outpatient Child Services, as well as from two Los Angeles schools for the emotionally disturbed. They were diagnosed independent of the research team by the Diagnostic Unit of UCLA’s Childhood Psychoses Clinical Research Center with the Interview for Childhood Disorders and Schizophrenia (ICDS; Russell et al., 1989). The reliability of the ICDS (kappa = 0.89) was determined on 23 cases (Russell et al., 1989). This interview includes questions that ensure an adequate assessment of schizophrenia and schizotypal personality disorder in children. It was derived from the Schedule for Affective Disorders and Schizophrenia for School-Age Children (Kiddie-SADS; Puig-Antich and Chambers, 1978) and the Diagnostic Interview for Children and Adolescents (DICA; Herjanic and Campbell, 1977). At the time of testing, 70% of the schizophrenic children were inpatients and 50% were on neuroleptic medication. The remaining children had not received neuroleptics for at least 2 weeks before their participation in the study. Children with a neurological, language, or hearing disorder were excluded from the study. The Kiddie Formal Thought
Disorder Story Game. A trained clinician administered the Story Game’s three parts (Caplan et al., 1989a). In the first and last part, the child heard an audiotaped story, retold the tale, and was asked standardized questions on each story. In the second part of the Story Game, the child was asked to make up a story chosen from four topics. The topics of all the stories were chosen because of their potential for eliciting pathological thought content in children. It was hoped that while the psychotic child was actively engaged in pathological thinking, the nonthreatening and indirect interview technique used in the Story Game would allow the child to be more expansive and reveal more FTD in his or her speech.
The Kiddie Formal Thought
Disorder Rating Scale (K-FTDS). Videotapes of the 20- to 2%min Story Game were rated with the K-FTDS by two trained raters who had no previous knowledge of the individual’s child’s diagnosis (Caplan et al., 1989~). The following synopsis presents an outline of the definitions of the K-FTDS signs. Illogical thinking was evaluated in three conditions. In the first condition, the child used causal utterances inappropriately. For example, “I left my hat in her office because her name is Mary.” In the second condition, the child presented the listener with unfounded and inappropriate reasoning in noncausal utterances. For example, “Sometimes I’ll go to bed and when I’m done laughing, I start wheezing and that’s when I relax.” In the third condition, the child contradicted himself or herself within one to two utterances by simultaneously making and refuting statements. For example, “I don’t like that story, but I liked it.” Ratings of loose associations were made when the child made an utterance that was offtopic without having previously prepared the listener for the topic change. For example: (Interviewer) “Why do you think that’s a reason not to like Tim?“(Child) “And I call my mom sweetie.” An utterance was rated as incoherence if the rater could not comprehend its contents because of scrambled syntax. For example: (Interviewer) “What happened next in your story?” (Child) “The day no witches no day goes.” Poverty of content of speech was rated if, in the presence of at least two utterances, the child did not elaborate on the topic of conversation. For example: “I suppose . . What? Maybe _.. Well, yes, I see. I suppose that’s all.” The scores derived from these ratings were frequency counts of illogical thinking, loose
172 associations, incoherence, and poverty of content of speech divided by the utterances during a 5-min sample of the Story Game. Due to the low base rate of and poverty of content of speech, they were not included in subsequent analyses. corrected kappa reliability statistic (Fleiss, 1973) was 0.78 and 0.71, respectively, thinking and loose associations (Caplan et al., 1989~).
number of incoherence The chancefor illogical
Table 1. Cognitive parameters, formal thought disorder scores, and medication status of the schizoohrenic children All children (n = 31) Data Mental age Chronological
age
Children with Span (n = 19)
Mean
SD
Mean
SD
9.3 10.3
2.00
9.7
2.00
1.51
10.4
1.5
Full scale IQ (WISC-R)
90
12.37
93
10.3
Verbal
88
16.31
94
12.2
93
16.27
95
14.7
IQ
Performance
IQ
7.1
2.19
7.3
2.08
Illogical thinking
0.33
0.29
0.23’
0.18
Loose associations
0.13
0.17
0.11
0.12
WISC-R
distractibility
factor score
Medication status On
16
NA
10
NA
Off
15
NA
9
NA
Note. Span = span of apprehension task. WISC-R z Wechsler lntelllgence
Scale for Children-Revised
1. The t test (t = 1.34, df = 48) was almost significant at the 0.1 level
The Wechsler Intelligence Scale for Children-Revised (WISC-R). The WISC-K was administered to all children by a psychometrist who was aware of the children’s diagnosis. The verbal comprehension (factor I), perceptual organization (factor 2), and distractibility (factor 3) WISC-R factor scores were derived from the WISC-R subscales according to Kaufman ( 1979). The Span of Apprehension. A subsample of I6 male and 3 female schirophrenic children were available to participate in the partial report span of apprehension task. These subjects had a mean chronological age, mental age, and full scale IQ of 10.4 (SD = I .47) years. 9.7 (SD = 1.99) years, and 93 (SD = 10.3), respectively (Table I). The span of apprehension task provides an index of the rate of visual information processing and is described in detail in Asarnow and MacCrimmon ( 1978, I9X I ). Data Analysis. We obtained FTD, WISC-R factor, and IQ scores on all 3 I schirophrenic children and span of apprehension data on I9 of the children. The relationships among the K-FTDS, WISC-R factor, IQ, and span of apprehension scores were computed using Pearson pairwise correlations. Due to the effects of age on the K-FTDS (Caplan et al., 19x9~) and span of apprehension scores (Asarnow and Sherman, 19X4), we partialled out chronological age from these correlations. We present only the partial correlations.
Results K-FTDS, (Table
2):
significantly
WISC-R Factor, and IQ Scores. We found the following relationships (I) Illogical thinking (ILL) and loose associations (LA) were not correlated
(rtt,t*,~~
= -0. I I, p <
0.5). (2) Loose
associations
were
173 negatively and significantly correlated with full scale IQ (~LA/FSIQ = -0.43, < 0.01) and the WISC-R distractibility factor (rLA/Fa&r 3 = -0.43, p < 0.02) but not with the verbal IQ (rLA,viQ = -0.26, p < 0.2) and performance IQ subscores (rLA,PiQ = -0.36, p < 0.05).(3) Illogical thinking was not significantly associated with full scale IQ (~ILL/FSIQ = 0.18, p < 0.4) verbal IQ (TILL/VIQ = 0.05, p < 0.7) performance IQ (rlLL/PlQ = 0.16, p < 0.3) or the distractibility factor scores nor illogical thinking (r ILL/ Factor 3 = 0.20, p < 0.3). (4) Neither loose associations was associated with the perceptual organization (rLA/Fa&r 2 = -0.29, p < 0.2; factor scores (rLA, Factor 1 = r ILL/ Factor 2 = 0.06, p < 0.7) or verbal comprehension -0.22, p < 0.2; rlLLIFactor 1 = 0.00&p < 0.9). The WISC-R distractibility factor score is composed of one verbal subscale, arithmetic, and three performance subscales, digit span, coding, and mazes. We therefore examined if the significant associations between loose associations and full scale IQ, and between loose associations and performance IQ, were primarily due to the distractibility factor subscales. After partialling out the variance from the distractibility factor scores, we found that loose associations were no longer significantly correlated with fullscale IQ (rLA/FS[Q = -0.29, p < 0.2) and performance IQ (~LA/PIQ = 0.09, p < 0.6). There was no change in the loose associations/verbal IQ association (~LA/VIQ = - 0.25, p < 0.2).
p
of Apprehension, K-FTDS, and WISC-R Factor Scores. The schizophrenic children with lower partial report span of apprehension scores had higher illogical thinking scores (rs pan,l~t =-0.42,p
Table 2. Correlation1 between K-FTDS, span of apprehension*, factor, and IQ scores in schizophrenic children Illogical Cognitive
measures
Span
thinking -0.42’
Loose associations
Span of apprehension
0.23
Factor
1
0.002
-0.21
-0.22
Factor
2
0.13
-0.29
0.28
Factor
3
0.20
-0.432
0.18
0.18
-0.434
0.15
0.05
-0.29
0.19
0.16
-0.36
0.13
-0.41 3
-0.372
0.24
Full
scale
Verbal
IQ
IQ
Performance Chronological
IQ age
WISC-R
Note. With the exceptron of the chronological age correlations, the correlations measures are presented after partialltng out chronological age. The correlations with the span of apprehension (Span) were computed on a subsample of 19 schizophrenic children. The remaining correlations were calculated for the 31 schizophrenic children. K-FTDS = Kiddie Formal Thought Disorder Story Game. WISC-R = Wechsler Intelligence Scale for Children-Revised. 1. p < 0.05 (remains significant after partialltng out the distractibrlity factor). 2. p < 0.02. 3. p < 0.01. 4. p < 0.01 (no longer significant after partialling out the distractibility factor score).
174 (‘Span/LA = 0.23, p < 0.3). The span of apprehension the schizophrenic children’s IQ measures and WISC-R
scores were also unrelated factor scores.
to
K-FTDS, Cognition, and Neuroleptic Medication. We investigated the effects of the medication status of the schizophrenic children on their FTD, WISC-R factor, IQ, and span of apprehension scores using t tests. There were no significant differences in the illogical thinking (t = 0.25, df = 29,~ > 0.2) span of apprehension (t = I .02, df = 17, p > 0.3), and WISC-R factor scores (t ~~~~~~1 = 0.2 I, df = 29, p > 0.2; t ~~~~~~2 = 0.12, df = 29, p > 0.2; t Factor 3 = 0.12, df = 25, p > 0.2) of the medicated and unmedicated subjects. Although the schizophrenic children on medication tended to have lower scores on loose associations than the unmedicated children, this difference was not significant (t = I .5, n = 29, p < 0.2). Discussion The results of this study suggest that loose associations and illogical thinking could represent different aspects of attention processing in schizophrenic children for the following reasons: (I) These two FTD signs were not correlated with each other and therefore appear to be independent clinical manifestations of FTD. (2) Each of the two K-FTDS signs had different cognitive correlates. Illogical thinking appears to be related to a deficit in momentary processing capacity, measured by the partial report span of apprehension task. Loose associations, however, appear to reflect “distractibility,” as indicated by a correlation with the WISC-R distractibility factor score. What is the possible clinical relevance of the significant associations between illogical thinking and the span of apprehension, and between loose associations and distractibility? The child with illogical thinking presents the listener with inappropriate reasoning. It is possible that the requirement to present the listener with logical reasoning taxes the schizophrenic child’s momentary processing capacity. In contrast, the child with loose associations unpredictably changes the topic of conversation without preparing the listener for the topic change. The cognitive demands of this situation could reflect distractibility more than reduced momentary processing capacity. Similar findings in adults lend credence to the major findings of this study. Converging with the first set of findings, Andreasen and Grove (1986) have suggested that in schizophrenic adults negative FTD signs, such as illogical thinking and poverty of content of speech, reflect the patients’ difficulty generating conversation. Nuechterlein et al. (1986) demonstrated that negative signs of schizophrenia were associated with impaired performance on the continuous performance test and the span of apprehension task that could have reflected processing overload. In support of our second set of findings, several studies reported a relationship between positive symptoms of schizophrenia, such as loose associations and distractibility, in adult schizophrenic patients (Cornblatt et al., 1985; Harvey et al., 1986, 1988; Oltmanns et al., 1979). Our findings that illogical thinking and loose associations reflect different aspects of attention/information processing in schizophrenic children, therefore, appear to be similar to those in schizophrenic adults.
175 There are two possible concerns about the generalizability of these findings. The first concern is the lower illogical thinking scores of the subsample for whom span of apprehension scores were available compared to those of the entire sample. It is unlikely, however, that reducing the range of illogical thinking scores would result in an increased illogical thinking/ span of apprehension correlation. The second concern is the tendency of neuroleptic medication to reduce the loose associations scores of the schizophrenic children. It is possible that this restricted range of loose associations scores could have affected the correlation with the span of apprehension scores. We are currently conducting a study to examine the effects of neuroleptic medication on the K-FTDS and span of apprehension measures in a larger sample of children. Our prediction that loose associations would also be associated with global cognitive dysfunction was based on our recent findings that schizophrenic and schizotypal children with higher loose associations scores had lower full scale and verbal IQ scores (Caplan et al., 1989b). By beginning to tease out the cognitive/ information processing correlates of this FTD sign in the study presented in this article, we have demonstrated that this FTD sign reflects specific attentional impairment and not global cognitive dysfunction. In conclusion, this is the first study to examine the relations among clinical measures of FTD, global measures of cognitive functioning (IQ), and specific measures of attention/information processing (WISC-R distractibility factor and span of apprehension) in schizophrenic children. We found an orderly set of correlations suggesting that individual are associated with specific attentional
symptoms processing
of FTD in schizophrenic capacities.
children
Acknowledgment. This study was supported by National Institute of Mental Health grants KOI-MH-00538 (R.C.), MH-16381 (J.G.F. and T.L.S.), and MacArthur Foundation grant MH-30897 (R.F.A.). Additional support was provided by grant MH-30897 from the National Institute of Mental Health to the UCLA Childhood Psychoses Clinical Research Center and by the UCLA Women’s Hospital Auxiliary. Technical assistance was given by Anne Brothers, Amy MO, Diane Putney, R.N., Diane Greene, and Chenga Buanausi. Sondra Perdue, Dr. M.P.H., also provided statistical consultation.
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