Where are the women in first-episode studies of schizophrenia?

Almost all investigations of first-episode schizophrenia uncover more male than female subjects. Two possible explanations for this observation are (1) first-episode investigations suffer more or less consistent methodologic biases or (2) the incidence of schizophrenia is higher in men than in women. Data from the markers and predictors of schizophrenia (MAP) project, a community-based first-episode study, permitted an investigation of the two alternatives. The results suggest that neither recruitment nor diagnostic vagaries explain the excess of males. Instead, the MAP results, consistent with other recent investigations, suggest that the incidence of schizophrenia is lower in women than in men. The findings are consistent with the literature on gender differences in schizophrenia, which indicates that schizophrenia in women is a less severe disorder than in men. The report includes recommendations for future first-episode investigations to ensure adequate representation of women.