Throughout the world, rates of depression are greater among females than males, and this gender gap emerges during adolescence and persists throughout adulthood. Until recently, women's health has centered on the topic of reproductive health, because research focused almost exclusively on biological and anatomical differences distinguishing men and women. Social and behavioral research on gender differences in health now employs multiple disciplinary frameworks and methodologies, and researchers seek to understand the higher rates of specific diseases and disorders in women and men. Symptoms of depression and the diagnosis of depression are more prevalent in women, and research that focuses on biological, psychological, and sociopolitical explanations for this gender gap should now be brought together to better inform efforts at treatment and prevention. Women and Depression is a handbook that serves to move toward a more integrative approach to women's depression in particular and mental health for all more generally.