Higher morbidity risk for schizophrenia in males: fact or fiction?

Male to female ratios in published annual incidence rates for schizophrenia range from 0.70 to 3.47. These variations between studies are attributed to differences in sampling, diagnostic criteria, design characteristics, and methods of calculation, which limit the quality of the studies. In an effort to overcome these shortcomings, we collected a comprehensive sample of 392 consecutive first admissions with a diagnosis of schizophrenia or a similar disorder out of a population of 1.5 million in a central region of western Germany. In this large representative sample, no significant gender differences in the incidence of schizophrenia could be detected regardless of different diagnostic definitions.