Women with major depression who go off their antidepressant medication during pregnancy are at risk of experiencing a relapse, a new study shows. However, even women who stay on their antidepressant may suffer a setback during pregnancy, according to the study.

Historically, the hormonal changes that occur during pregnancy have been viewed as providing protection against the onset of new depression and the risk of relapse - and that antidepressants should be discontinued, especially in the first trimester, due to potential risks to the growing baby.

“Our data suggest that this is not the case,” warn Dr. Lee Cohen, of Massachusetts General Hospital and Harvard Medical School in Boston and colleagues in this week’s Journal of the American Medical Association.

While some women may experience feelings of well being during pregnancy, the results of the study suggest that pregnancy is not “uniformly protective” with respect to risk of relapse of major depression.

With funding from the National Institute of Mental Health, Cohen’s team determined the risk of experiencing a relapse of major depression in 201 pregnant women who elected to maintain, change the dosage or discontinue antidepressant medication during their pregnancy.

Eighty-two maintained treatment, 65 discontinued, 34 decreased and 20 increased their drug therapy for depression during pregnancy.

Overall, 86 of 201 women (43 percent) experienced a relapse of major depression while pregnant. This included 26 percent of women who stayed on their antidepressant medication and 68 percent who went off it while pregnant. A depression relapse also occurred in 45 percent of the women who increased their medication and 35 percent who decreased drug treatment.

Depression is highly prevalent in women and frequently has its onset during the childbearing years, Cohen and colleagues point out. With greater awareness and increasing treatment of depression, more and more women may face a decision regarding use of antidepressant medication during pregnancy.

It’s not an easy decision to make, Cohen and colleagues pointed out, adding that women and their doctors must consider the potential risks to the fetus of exposure to antidepressant medication as well as the potential impact of untreated depression in the mother-to-be.

SOURCE: Journal of the American Medical Association, February 1, 2006.