Here’s an interesting article on WebMD by Miranda Hitti about the relationship between depression and menstrual cycles.

Jan. 28, 2005 — Most women with depression get worsening symptoms prior to their periods, researchers say.
In a new study, 64% of women with major depression said their symptoms get worse five to 10 days before their period. Women whose symptoms worsened had depression for a longer duration of time than women whose depression symptoms did not change because of the onset of menstruation.
The news could help doctors evaluate, treat, and set standards for the treatment of depression. Nearly 19 million American adults have depression in any given year — about 9.5% of the population. Women experience depression about twice as often as men, says the National Institute of Mental Health (NIMH).

That may be partly due to factors that are unique to women. However, men are less likely to admit depression and doctors are less likely to suspect it in their male patients, says NIMH.
Depression can strike at any age. Everything from genetics to stress can play a role. According to researchers more then 20% of women will experience depression at some time during their lifetime. But the childbearing years may be a particularly vulnerable time for women.
The study appears in the January issue of Psychological Medicine. It’s the work of researchers including Susan Kornstein, MD, of Virginia Commonwealth University (VCU).
Tracing Depression
The participants were 433 women with major depression. None had gone through menopause or were taking oral contraceptives. They had enrolled in a larger depression study backed by the National Institute of Mental Health that’s still underway.
Premenstrual worsening of depression was reported by 64% of the women. These women also reported a longer current depressive episode — nearly 30 months, compared with 13.5 months for women who said their depression didn’t worsen before menstruation.
“Based on our findings, this type of symptom pattern is very common, especially in women who have chronic courses of depression,” says Kornstein, in a news release.
Kornstein is a psychiatry and obstetrics-gynecology professor at VCU’s medical school. She is also the executive director of the university’s Institute for Women’s Health and Mood and Disorders Institute.
The news could mean that the menstrual cycle should be considered in depression treatment.
“For example, if you start a depressed woman on an antidepressant medication and she comes back a week later feeling worse, it may be because she is premenstrual now and not that it was the wrong choice of antidepressant,” says Kornstein, in the news release.
The women whose depression worsened before menstruation also had a couple of other things in common. They were slightly older and tended to be in worse health. In particular, they were more likely to have body aches and pains, gastrointestinal problems, and muted moods.
However, there was no difference among the women regarding suicidal thinking or changes in sleep, appetite, or sexual interest.
They say the next step of their research will be to determine whether there are differences in response to treatment to various types of medications and psychotherapy in women with and without worsening of symptoms prior to menses.