Evidence for early-childhood, pan-developmental impairment specific to schizophreniform disorder: results from a longitudinal birth cohort.

BACKGROUND Childhood developmental abnormalities have been previously described in schizophrenia. It is not known, however, whether childhood developmental impairment is specific to schizophrenia or is merely a marker for a range of psychiatric outcomes. METHODS A 1-year birth cohort (1972-1973) of 1037 children enrolled in the Dunedin Multidisciplinary Health and Development Study was assessed at biennial intervals between ages 3 and 11 years on emotional, behavioral, and interpersonal problems, motor and language development, and intelligence. At age 11 years, children were asked about psychotic symptoms. At age 26 years, DSM-IV diagnoses were made using the Diagnostic Interview Schedule. Study members having schizophreniform disorder (n = 36 [3.7%]) were compared with healthy controls and also with groups diagnosed as having mania (n = 20 [2%]) and nonpsychotic anxiety or depression disorders (n = 278 [28.5%]) on childhood variables. RESULTS Emotional problems and interpersonal difficulties were noted in children who later fulfilled diagnostic criteria for any of the adult psychiatric outcomes assessed. However, significant impairments in neuromotor, receptive language, and cognitive development were additionally present only among children later diagnosed as having schizophreniform disorder. Developmental impairments also predicted self-reported psychotic symptoms at age 11 years. These impairments were independent of the effects of socioeconomic, obstetric, and maternal factors. CONCLUSIONS The results provide evidence for an early-childhood, persistent, pan-developmental impairment that is specifically associated with schizophreniform disorder and that predicts psychotic symptoms in childhood and adulthood.