Sex differences in schizophrenia, a review of the literature

Objective: To comprehensively and critically review the literature on gende r differences in schizophrenia. Method: An initial search of MEDLINE abstracts (1966-1999) was conducted us ing the terms sex or gender and schizophrenia, followed by systematic searc h of all relevant articles. Results: Males have consistently an earlier onset, poorer premorbid functio ning and different premorbid behavioral predictors. Males show more negativ e symptoms and cognitive deficits, with greater structural brain and neurop hysiological abnormalities. Females display more affective symptoms, audito ry hallucinations and persecutory delusions with more rapid and greater res ponsivity to antipsychotics in the premenopausal period but increased side effects. Course of illness is more favorable in females in the short- and m iddle-term, with less smoking and substance abuse. Families of males are mo re critical, and expressed emotion has a greater negative impact on males. There are no clear sex differences in family history, obstetric complicatio ns, minor physical anomalies and neurological soft signs. Conclusion: This review supports the presence of significant differences be tween schizophrenic males and females arising from the interplay of sex hor mones, neurodevelopmental and psychosocial sex differences.