Beware of mood disorders that look like PMDD. (Major Depressive Disorder, Dysthymia).

BALTIMORE -- Intermittent treatment with fluoxetine each month can greatly ease a woman's premenstrual dysphoric disorder--but can mean undertreatment if she has major depression.

And such an approach could catapult a woman with unrecognized bipolar disorder into mania, Dr. Karen L. Swartz warned at a mood disorders symposium sponsored by the Depression and Related Affective Disorders Association.

In women with major depressive disorder, bipolar disorder, or dysthymia, the symptoms can worsen during the luteal phase, thereby mimicking PMDD. A woman with any of these mood disorders may present to her psychiatrist, ob.gyn., or primary care provider with the complaint that she feels increased depression, anxiety, and affect lability in the week preceding onset of menses.

"What I see very commonly in my practice is women with ongoing major depressive symptoms that then worsen in the premenstrual period," said Dr. Swartz of the department of psychiatry and behavioral sciences at the Johns Hopkins University, Baltimore.

Physicians are more likely to encounter women with major depression than with PMDD because 15%-20% of women have major depression at some time in their lives while only 3%-5% have PMDD, she noted.

A primary care physician can readily do the careful assessment that is needed to distinguish between such mood disorders. An estimated 80% of women of reproductive age have some degree of premenstrual mood changes, so clearly there are not enough psychiatrists to handle their evaluation, Dr. Swartz said.

The best way to evaluate such patients is to have them keep a daily symptom diary for at least 2 months. A woman with PMDD will develop five or more ...