Gender differences in mental health disorders may serve as a useful heuristic for integrating epidemiological and psychobiological data. The vast majority of mental disorders may express major gender-related variations in prevalence, natural history, symptoms, prognosis, and treatment outcome.

To compare demographic and clinical characteristics of women and men admitted to a psychiatric unit.

Retrospective data of all the patients admitted to a psychiatric inpatient unit, from January 2004 to December 2007, were reviewed. The demographic and clinical characteristics of the two genders were compared.

Of a total of 1114 patients admitted, 53.1% were women. They differed significantly from male inpatients in being older (46.7 vs. 40.7 years), less frequently black (14.6 vs. 25.4%), more frequently diagnosed with bipolar and delusional disorders, and in receiving fewer diagnosis of schizophrenia. Women had a longer average length of stay, a different seasonal pattern in admissions, with a much lower rate of admissions than men in December (38.6 vs. 61.4%), and a lower percentage of patients with three or more readmissions. Only 37.2% of the 180 compulsory admissions were of women.

There are significant differences in clinical and demographic characteristics of female and male psychiatric inpatients. While some results may be explained by gender specific biological factors (as in the type of diagnosis), others are probably associated with different gender roles (as in the seasonality of admissions).