A prospective cohort study of childhood behavioral deviance and language abnormalities as predictors of adult schizophrenia

Language and behavioral deviance in early childhood in preschizophrenia ind ividuals suggests that the pathologic processes predisposing to schizophren ia are present from early in life. However, the etiologic antecedents of su ch impairments, and the degree to which they predict adult schizophrenia, h ave not been conclusively demonstrated. To address this, me examined langua ge and behavioral predictors of adult psychiatric outcome in a population c ohort (72 individuals with schizophrenia or schizoaffective disorder, 63 of their unaffected siblings, and 7,941 with no diagnosis) evaluated prospect ively with behavioral examinations and a speech and language evaluation at 8 months, 4 years, and 7 years of age. Psychiatric outcome was ascertained via adult treatment contacts, and diagnoses were made by chart review accor ding to DSM-IV criteria. Social maladjustment at age 7 was found to predict adult schizophrenia, and focal deviant behaviors (e.g., echolalia, meaning less laughter) at ages 4 and 7 were significantly associated with both schi zophrenia and sibling status. Unintelligible speech at age 7 was a highly s ignificant predictor of adult schizophrenia (odds ratio = 12.7), and poor e xpressive language ability predicted both schizophrenia and unaffected sibl ing outcome. Early behavioral and language dysfunction did not differential ly characterize preschizophrenia subjects with a history of fetal hypoxia o r an early age of first treatment contact. Given that unaffected siblings s how similar signs of deviance, such problems may indicate genotypic suscept ibility to the disorder, or shared environmental influences, or both.