DO OBSTETRIC COMPLICATIONS CAUSE THE EARLIER AGE AT ONSET IN MALE THAN FEMALE SCHIZOPHRENICS

We compared the age at onset of 184 patients with functional psychoses with and without a history of obstetric complications (OCs) as define d by the scale of Lewis et al. (1989). OCs had no significant influenc e on the age at onset in those patients who had affective psychoses or were non-white. There were 73 white patients with a DSM-III-R diagnos is of schizophrenia. The mean age at onset of those 25 who had a histo ry of at least one definite OC was 2.6 years earlier than that of the 48 patients with no history of OCs. This effect was entirely due to th e male patients with histories of OCs who had, on average, a 3.5 years earlier age at onset. There were no gender differences in age at onse t among schizophrenics without a history of OCs. We suggest that a sub group of male patients with a history of OCs is responsible for the ea rlier age at onset in male compared to female schizophrenics.