Gender differences in depression: historical changes.

Depression has been widely reported to be more prevalent among females than among males. In this study we demonstrate that gender differences in depression occur only among individuals born during particular historical periods, and test the utility of a model focusing on changes in women's opportunities for academic and professional achievement in predicting periods of significant gender differences in depression. Based on reanalysis of data reported by Klerman et al., we find gender differences in depression among people 40 years of age and older to be high among cohorts that reach adolescence during periods of increasing opportunities for female achievement. Among cohorts that reach adolescence during periods of stable or decreasing opportunities for women, gender differences in depression are not significant at any age.