Neurodevelopmental Pathways in Schizophrenia.

We examined early-onset schizophrenia as a neurodevelopmental disorder. These data are from a 2-year longitudinal prospective study of youth with psychotic disorders. Standardized diagnostic and neuropsychological assessments include: Structured Clinical Interview for Diagnostic and Statistical Manual (DSM)-IV; Diagnostic Interview for Children and Adolescents, Revised; Premorbid Adjustment Scale; Wechsler Intelligence Scale for Children-III; the Wisconsin Card Sorting Test (WCST), and the California Verbal Learning Test. Pertinent family and developmental history are obtained via parent interviews and chart review. Forty-eight subjects have been recruited to date; 17 with schizophrenia, 13 with bipolar disorder, 10 with psychosis nos, seven with schizoaffective disorder, and one with an organic psychosis. Subjects with schizophrenia had higher ratings of premorbid social withdrawal and dysfunctional peer relationships. All groups had high rates of cognitive impairment, prenatal/perinatal complications, and comorbid psychiatric disorders. Homotypic family psychiatric history was associated with diagnosis in youth. Our data are consistent with a neurodevelopmental model, whereby specific genetic/neurological risk factors and nonspecific biologic/environmental modulating factors interact in the development of schizophrenia and other psychotic disorders.