Women who are unhappily married, divorced, or separated, have high rates of major depression. The rates are lower for those who are happily married. While clinical depression usually occurs for the first time when a person is between the ages of 20 and 50, people over the age of 65may be especially vulnerable. According to some estimates, approximately one-half of those who have developed depression will experience it again. Also, having a close relative with bipolar disorder may increase a person's chances of developing major depression.
Bipolar disorder is diagnosed in equal numbers of men and women.
It is not known for sure why major depression seems to affect more women than men while mania affects both equally. One reason may be that mania, with its very conspicuous symptoms, is much more easily recognized than depression. Depression may also go unrecognized in men. Most of those who have had an episode of mania once will have a second. People who have relatives who have had bipolar disorder have a greater chance of developing it themselves.