BACKGROUND The study tests the hypothesis that juvenile-onset schizophrenia is associated with premorbid developmental impairments. It was predicted that the pattern of developmental impairments would vary with age of onset and with gender.
METHOD A case-control design was used to examine developmental impairments in 61 consecutive juvenile-onset (age 7-17) referrals with ICD-9 schizophrenia; 61 non-psychotic psychiatric controls were matched on age and gender. Cases and controls were divided into childhood-onset (age 7-13) and adolescent-onset (age 14-17).
RESULTS The schizophrenic cases had a significantly higher risk of premorbid social (chi 2 = 9.1, P < 0.005), motor (chi 2 = 9.1, P < 0.005) and language impairments (chi 2 = 10.1, P < 0.005). Specific impairments of language production and comprehension were associated with childhood-onset schizophrenia and were independent of gender.
CONCLUSIONS Juvenile-onset schizophrenia is associated with a range of developmental antecedents. There may be a specific link between cases with a very early onset and an impairment in the processes underlying the development of language.