The short answer is “yes.” A woman is approximately twice as likely to have a major depressive disorder or dysthymia (a less severe, more chronic depression) than a man. In bipolar, or manic-depressive, disorder, however, the sex ration is about the same. The preponderance of women among the ranks of the depressed is well studied and repeatedly demonstrated.
In a large study, 7 percent of women had major depression in their lifetimes as opposed to 2.6 percent of men. The difference appears to hold in other cultures as well and begins to assert itself around puberty. However, when depression occurs, the severity or course of the illness does not appear to be different between the sexes.
The next question is, Is this apparent difference in rates of depression a real one? Are there differences in the way women express emotions and seek and accept help that falsely makes them appear to have more depression? Men, we have reason to think, conceal their depressions. (See Terrence Real’s book I Don’t Want to Talk About It.) So are the rates of women’s “depressions” inflated by women’s emotional availability and men’s reduced by their concealment? The big survey studies, which use diagnostic methods that penetrate these disguises, indicate that the difference between men and women appears to be real.
What accounts for the difference? There have been possible biological explanations — most prominently, the role of female hormones and hormone-intensive events, such as menses, pregnancy and childbirth, and menopause, which are known to be associated with emotional changes and depression. Many women have premenstrual sadness and irascibility; some have frank and significant depression. Postpartum depression is a well-known event, and menopause, in the popular mind, is linked to depression and emotional upheaval.
Yet despite the obvious relevance of these states to particular women, using hormonal changes to explain broad differences between the sexes has not stood up well. Premenstrual mood changes are generally mild, and when severe, are often related to preexisting depressive and other disorders. (The menstrual cycle seems to act as a channeler or lightening-rod rather than as a cause.) Depressions around childbirth are occasionally related to hypothyroidism. Mostly, they are associated with preexisting vulnerabilities to depression and life stresses, including, of course, the stress of becoming a mother.
As for menopause, there is no evidence that particularly large numbers of women become depressed at that time. Those women who do are often faced with life issues, such as changing roles and socioeconomic problems, that were long in the making, before hormone levels declined. For all the obvious attractiveness of biological-hormonal theories, other theories related to differences in culture, experience, psychological makeup, and socioeconomic status keep poking up their heads.
What if factors that are known to predispose a person to depression are more common in women? These factors include low socioeconomic status, low education, being widowed, being abused, traditional feminine role, house-bound labor and social isolation, and adverse life events.
Other explanations combine biological and cultural factors and look to childhood events or patterns, such as sexual abuse, which may have led to subtle nervous system damage, predisposing the person to later depression. Again, these events might be supposed to be more common in females.
Understanding sex differences turns out to be a very difficult and complicated business. In the absence of solid answers, it is tempting to indulge in some pet theory or ideologically-inspired notion. But keep in mind, when you hear someone speaking with great confidence on the subject, his or her opinions are not based on the current state of knowledge.