Premorbid social functioning in schizophrenia and bipolar disorder: similarities and differences.

OBJECTIVE: This research examined social functioning in childhood and adolescence among patients with schizophrenia and patients with bipolar disorder compared with healthy subjects and investigated the relation between premorbid adjustment and risk factors for psychosis.
METHOD: Maternal recall was used to assess the premorbid adjustment of patients with schizophrenia (N = 70) and patients with bipolar disorder (N = 28) recruited from a survey of consecutive hospital admissions for psychosis and of healthy comparison subjects (N = 100) drawn from the same catchment area.
RESULTS: The patients with schizophrenia had significantly poorer premorbid adjustment in childhood and adolescence than the comparison subjects and were impaired in both sociability and school adjustment. The patients with bipolar disorder exhibited poorer social impairment in adolescence than the comparison subjects, though to a lesser degree than the schizophrenic subjects, but functioned well at school. There were significant linear trends in the risk of psychosis with worsening premorbid functioning, which was most marked in the schizophrenic group, and a specific linear relation between low birth weight and poor premorbid adjustment among the schizophrenic patients.
CONCLUSIONS: Impaired premorbid social functioning is not specific to schizophrenia and is seen also in bipolar disorder. The data support the view that poor premorbid social adjustment is one manifestation of vulnerability to adult psychotic disorders. These results are consistent with other findings pointing to early developmental deficits in patients who subsequently develop psychosis.