Generalizability of first-episode studies in schizophrenia

Over a 5-year period, 77 patients in their first episode of psychosis were recruited into a study of autoimmune factors in the pathogenesis of schizophrenia. In this article their demographic and clinical characteristics are compared to those of chronic patients recruited into the same study as well as to the entire outpatient population of a schizophrenia clinic in a Pittsburgh community mental health center. There were no significant demographic differences between the first-episode patients and either of the other groups of schizophrenic patients. There was a significantly higher proportion of black subjects in the clinic population compared to the catchment area from which they were drawn. Clinically, first-episode patients differed from chronic patients in having fewer negative symptoms and more of certain positive symptoms. Age of onset was not significantly different in male and female first-episode cases, although there was a trend of females to be slightly older. We conclude that if diagnosis includes followup and reassessment, findings from research cohorts such as ours can be generalized to populations of outpatient schizophrenic subjects volunteering for treatment.