The first drug for women suffering postpartum depression received federal approval, a move likely to pave the way for a wave of treatments to address a debilitating condition that is the most common complication of pregnancy.

The drug, a synthetic version of a naturally occurring hormone, may be a significant improvement over available antidepressants because it works quickly, within 48 hours. Most antidepressants take two to four weeks to ease symptoms, if they work at all.

“Postpartum depression is a serious condition that, when severe, can be life-threatening,” said Dr. Tiffany Farchione, acting director of the Division of Psychiatry Products at the Food and Drug Administration’s Center for Drug Evaluation and Research.

There are limitations to the drug, brexanolone, which will be marketed as Zulresso. It is delivered by infusion over 60 hours, during which a new mother must remain supervised in a medical center. The infusion will be expensive, $20,000 to $35,000, not including the costs of the hospital stay.

Clinical trials of the drug, all sponsored by manufacturer Sage Therapeutics, found that the relief from depression continued for a month after the treatment. A pill version, which would be much more accessible and easier for patients, is showing promise in its clinical trials, Sage said.

“The major thing is, of course, the rapid effect,” said Dr. Margaret Spinelli, a clinical professor of psychiatry at Columbia University. “That it’s the first that’s designed for postpartum depression is important and means it will probably be a segue to design other medications for postpartum depression to be administered in an easier way.”