A major drug company has recently repackaged its SSRI antidepressant as a treatment for Premenstrual Dysphoric Disorder. Consumers may wonder:  How does that differ from PMS?

In community studies of women who menstruate, About 11% to 32% of women report some mood changes and physical discomfort associated with the menstrual cycle. About 3% to 9% report mood changes severe enough to be considered PMDD by current medical definitions. That is, they have a severe premenstrual mood shift. (depressed mood, hopelessness, anxiety, affective lability, anger, or irritability). A diagnosis of PMS is more often made when the most troublesome premenstrual symptom is physical discomfort.

The most credible studies of diet and supplements indicate that calcium supplements may help some women with premenstrual symptoms. Multiple studies have shown that antidepressant drugs of the SSRI type may be immediately effective for many with PMDD, when taken in low doses as needed during the afflicted woman's cycle. (This is unlike the SSRI action upon depression, which typically takes several weeks to kick in.) The SSRI's also often improve many physical PMS symptoms in many cases.

Women with depression may experience an additional worsening of mood pre-menstrually, but this is not considered PMDD - that label is only applied if mood is usually fine. However, some women would far rather be diagnosed as having a temporary and cyclical condition, than diagnosed as having a "mental illness" such as depression. They may  seek treatment for premenstrual symptoms only. Unfortunately, a gynecologist or an internist or indeed a psychiatrist may neglect to ask whether the rest of the month is miserable, as well.

If you have a worsening of mood pre-menstrually, keeping a daily mood diary for two or three months may help in attaining a correct diagnosis. A simple numerical rating (e.g. 1-suicidal, 10-ridiculously happy) for the day should suffice.