Inclusion of Women and Gender-Specific Analyses in Randomized Clinical Trials of Treatments for Depression

BACKGROUND: The higher prevalence and cost of depression for women compared with men and the possible gender differences in treatment response demand the inclusion of women in clinical trials of depression treatments. The 1993 National Institutes of Health (NIH) Revitalization Act set a new standard, requiring investigators to consider the inclusion of women and analyze outcomes by gender, yet compliance with these standards in depression research has not been examined systematically. The purpose of this study is to examine the inclusion of women and gender-specific analyses in recent randomized clinical trials (RCTs) for depression. METHODS: RCTs were identified through a MEDLINE search for trials published between January 1 and December 31, 2007, and a Clinicaltrials.gov search of self-identified interventional studies to treat depression. RESULTS: Of the 150 RCTs for depression published in 2007, 15% did not report the gender composition of their sample, 50% of studies did not analyze outcomes by gender, and 12% controlled for gender but did not analyze for gender differences. Of the 768 trials reviewed on Clinicaltrials.gov, 89% reported recruiting male and female participants, yet <1% reported an intention to analyze results by gender. CONCLUSIONS: Many recent studies of depression treatments include women but do not examine outcomes by gender. Understanding how women differ from men in response to treatment is critical for enhancing treatment efficacy for the greatest number of adults with depression.