Schizophrenia and the myth of intellectual decline.

OBJECTIVE The authors' goal was to investigate the issue of intellectual deterioration in schizophrenia. METHOD They examined the childhood IQs of adult patients with schizophrenia who had attended a child psychiatry service where measurement of intelligence was routine. Follow-up IQs of 34 of these patients were obtained an average of 19.4 years later. RESULTS The mean child and adult IQs were greater than one standard deviation lower than those of the general population. There were no significant differences between the child and adult IQs, however, suggesting that the impairment in intelligence during childhood was stable over the follow-up period. CONCLUSIONS The deficit in intellectual function observed in these patients, and reported in the literature, is lifelong and predates the onset of schizophrenia.

[1]  A. David,et al.  Premorbid neuropsychological performance as a risk factor for schizophrenia: 13-Year follow-up of 50 000 conscripts , 1995, Schizophrenia Research.

[2]  M Marmot,et al.  Child developmental risk factors for adult schizophrenia in the British 1946 birth cohort , 1994, The Lancet.

[3]  R. Murray,et al.  Neurodevelopmental Schizophrenia: The Rediscovery of Dementia Praecox , 1994, British Journal of Psychiatry.

[4]  T. Goldberg,et al.  Is There Cognitive Decline in Schizophrenia? , 1994, British Journal of Psychiatry.

[5]  A. Canavan,et al.  Deriving principal component IQ scores from the WAIS-R. , 1993, The British journal of clinical psychology.

[6]  C. Frith,et al.  IV. Performance on Psychological Tests. Demographic and Clinical Correlates of the Results of these Tests , 1991, British Journal of Psychiatry.

[7]  J. Ragland,et al.  Neuropsychological assessment of monozygotic twins discordant for schizophrenia. , 1990, Archives of general psychiatry.

[8]  T. Barnes,et al.  Cognitive functioning and symptomatology in chronic schizophrenia , 1990, Schizophrenia Research.

[9]  R. Murray,et al.  Is schizophrenia a neurodevelopmental disorder? , 1987, British medical journal.

[10]  D. Weinberger Implications of normal brain development for the pathogenesis of schizophrenia. , 1987, Archives of general psychiatry.

[11]  A. Canavan,et al.  Principal components of the WAIS–R , 1986 .

[12]  E. Robins,et al.  Research diagnostic criteria: rationale and reliability. , 1978, Archives of general psychiatry.

[13]  T. Crow,et al.  CEREBRAL VENTRICULAR SIZE AND COGNITIVE IMPAIRMENT IN CHRONIC SCHIZOPHRENIA , 1976, The Lancet.

[14]  D. Offord,et al.  School Performance of Adult Schizophrenics, Their Siblings and Age Mates , 1974, British Journal of Psychiatry.

[15]  D. Offord,et al.  Adult schizophrenia with scholastic failure or low IQ in childhood. A preliminary report. , 1971, Archives of general psychiatry.

[16]  R. Hamlin THE STABILITY OF INTELLECTUAL FUNCTION IN CHRONIC SCHIZOPHRENIA , 1969, The Journal of nervous and mental disease.

[17]  G. Albee,et al.  On childhood intellectual decline of adult schizophrenics: a reassessment of an earlier study. , 1968, Journal of abnormal psychology.

[18]  A. Smith MENTAL DETERIORATION IN CHRONIC SCHIZOPHRENIA , 1964, The Journal of nervous and mental disease.

[19]  G. Albee,et al.  Childhood and intercurrent intellectual performance of adult schizophrenics. , 1963, Journal of consulting psychology.

[20]  H. L. Williams,et al.  Direct measurement of cognitive deficit in schizophrenia. , 1962, Journal of consulting psychology.

[21]  A. Schwartzman,et al.  Intellectual loss in schizophrenia: Part II. , 1962 .

[22]  W. B. Webb,et al.  An attempt to study intellectual deterioration by premorbid and psychotic testing. , 1950, Journal of consulting psychology.

[23]  E. Walker,et al.  Intelligence in schizophrenia: meta-analysis of the research. , 1984, Schizophrenia bulletin.

[24]  A. Kaufman Intelligent testing with the WISC-R , 1979 .

[25]  D. Wechsler Manual for the Wechsler Adult Intelligence Scale. , 1955 .