CHICAGO -- Pregnant women who stop taking antidepressants run a high risk of slipping back into depression, a study found, contrary to the belief that the surge of hormones during pregnancy keeps mothers-to-be happy and glowing.
Many doctors have assumed that pregnancy is a time of emotional well-being that protects women against mental illness. But the study in today's Journal of the American Medical Association found that chronically depressed women who stopped taking antidepressants during pregnancy relapsed five times more often than pregnant women who continued taking the pills.
''It's important that patients not assume that the hormones of pregnancy are going to protect them from the types of problems they've had with mood previously," said study coauthor Dr. Lee S. Cohen of Massachusetts General Hospital, which specializes in pregnancies of women with psychiatric disorders.
The study does not advise mothers-to-be whether to take antidepressants, but it highlights the need for women and their doctors to balance the risk of medications harming the fetus against the danger of untreated depression. One study has linked several antidepressants to breathing and respiratory problems in newborns, while the US Food and Drug Administration last month warned pregnant women that their fetus could be at higher risk of heart defects from taking the drug Paxil.
On the other hand, untreated depression during pregnancy may also be bad for the fetus, according to other studies. And Cohen pointed out that depression during pregnancy often foreshadows postpartum depression, which can mean lower quality care for the newborn. ''For patients with a history of depression who are . . . doing well as they consider pregnancy, they really have to discuss with their clinicians what the plan will be," said Cohen, who worked with researchers from UCLA and Emory University in Atlanta.
Researchers followed 201 pregnant women with histories of major depression who were taking drugs such as Prozac, Zoloft, Effexor, and Paxil. Because of ethical concerns, the researchers did not randomly assign the women to either stop or continue medication. Instead, the women decided what to do, then researchers watched what happened. Sixty-eight percent of those who stopped taking antidepressants slipped into depression compared with 26 percent of women who continued taking their medications. After adjusting for differences between the two groups, the authors concluded women who dropped their medications had a fivefold higher risk of relapse.
The study was funded by the National Institute of Mental Health. Two of the coauthors declared in the paper that they have financial ties to several antidepressant manufacturers.
Scott Allen of the Globe staff contributed to this report.