Pregnant women who stop taking antidepressants run a high risk of slipping back into depression, a study found, busting the myth that the surge of hormones during pregnancy keeps mothers-to-be happy and glowing.
The study offers new information but no clear answers for expectant mothers who must balance the risk of medications harming the fetus against the danger of untreated depression.
"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 co-author Dr. Lee Cohen of Massachusetts General Hospital.
The study does not deal with postpartum depression — the depression that sets in after delivery, and is often blamed on hormonal changes. The research looks only at depression during pregnancy, a condition far less understood.
No one knows how many pregnant women are on antidepressants, but it is safe to say millions of women of childbearing age take them. Medco Health Solutions estimates 8.4 million American women ages 20 to 44 take antidepressants.
Other research has shown risks to the fetus, including possible heart defects, from antidepressant use during pregnancy.
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. They were five times more likely to suffer a relapse than the women who continued on drugs.
But staying on antidepressants did not shield expectant mothers from depression entirely; 26 percent of those who continued drug treatment became depressed anyway.
Dr. Katherine Wisner of the University of Pittsburgh School of Medicine said the study makes an important contribution by quantifying the risk of relapse. She was not involved in the study but does similar work.
"I was taught in my residency that women don't get depressed during pregnancy," said Wisner, who was a psychiatry resident in the early 1980s. But "I had patients who were depressed. I asked my supervisor, `You mean I'm really not seeing patients who are depressed?'"
The study appears in Wednesday's Journal of the American Medical Association and was funded by the National Institute of Mental Health. Two of the co-authors declared in the paper that they have financial ties to several antidepressant manufacturers.
Other researchers have shown that antidepressant use during the last three months of pregnancy can make newborns jittery and irritable, and sometimes can cause them serious breathing problems. In addition, the Food and Drug Administration has warned that Paxil may be linked to fetal heart defects when taken during the first three months of pregnancy.
Dr. Peter Kramer, author of "Listening to Prozac" and "Against Depression," said the study provides information that can help women and doctors decide what to do.
"Ideally, everyone would like to go through pregnancy off all medication," Kramer said. "But these are serious issues, and both decisions can be justified."
Kramer suggested some women might want to get off antidepressants but schedule more psychotherapy while pregnant.