It was hypothesized that women are more vulnerable to depressive symptoms than men because they are more likely to experience chronic negative circumstances (or strain), to have a low sense of mastery, and to engage in ruminative coping. The hypotheses were tested in a 2-wave study of approximately 1,100 community-based adults who were 25 to 75 years old. Chronic strain, low mastery, and rumination were each more common in women than in men and mediated the gender difference in depressive symptoms. Rumination amplified the effects of mastery and, to some extent, chronic strain on depressive symptoms. In addition, chronic strain and rumination had reciprocal effects on each other over time, and low mastery also contributed to more rumination. Finally, depressive symptoms contributed to more rumination and less mastery over time.