The paper reviews epidemiological studies and explanatory models related to gender, social roles and depression symptoms. We conclude that women in Taiwan have a higher depression prevalence than men. The younger and the elderly also have higher depression risks than that of the middle aged group. In terms of social role effect, being a mother has a negative effect on women's mental health, but being a father has a protective effect. In addition, multiple roles help men's mental health but not on women's condition. In this paper, the mental health related policy applications are also discussed.