The Food and Drug Administration announced Friday it has approved the first oral treatment for postpartum depression. The drug, called zuranolone, is a once-a-day pill that will be branded as Zurzuvae by drugmakers Sage Therapeutics and Biogen. 

Zuranolone is approved for use in adults for the treatment of postpartum depression, an episode of major depression that can begin after childbirth or the later stages of pregnancy, which affects an estimated 15% of women in the weeks or months after having a baby.

"Having access to an oral medication will be a beneficial option for many of these women coping with extreme, and sometimes life-threatening, feelings," Dr. Tiffany Farchione, director of the Division of Psychiatry in the FDA's Center for Drug Evaluation and Research, said in a statement.

The pill is meant to be taken for just two weeks, and the companies say many patients start to see improvement quickly.

"Women were reporting rapid improvement in their depression as early as day three," said Dr. Kristina Deligiannidis, professor at the Institute of Behavioral Science at the Feinstein Institutes for Medical Research in New York.

Deligiannidis led the study of the drug in the past and has worked as a paid consultant for Sage and Biogen.

Postpartum depression can be severe, and for some women may last months or even years.

"This is not the baby blues. This is not the transient normal fluctuation of hormones that can affect our mood after delivery and then go away on its own," Deligiannidis said.

Before this, the only approved option for treating postpartum depression was also from Sage Therapeutics: brexanolone, which is marketed as Zulresso and must be administered as an IV infusion. It was approved by the FDA in 2019 as the first treatment specifically for postpartum depression.

Similar to that drug, Sage and Biogen say they think zuranolone works as a fast-acting steroid that binds to GABA receptors within the brain, effectively resetting neurotransmitters thrown off in patients struggling with depression.

"In people with depression, it may help to rapidly rebalance dysregulated neuronal networks to help restore brain function. Zuranolone targets brain networks responsible for functions such as mood, arousal, behavior, and cognition," the companies said in a release last year.

Zuranolone's label will carry a boxed warning that patients should not drive or operate machinery for 12 hours after taking the drug.  The FDA says the most common side effects include drowsiness, dizziness, diarrhea, fatigue, the common cold and urinary tract infection. There is a risk of suicidal thoughts. The drug may cause fetal harm, so women taking it should use contraception, the FDA says. 

Sahar McMahon took part in the clinical trial after developing depression and feelings of anxiety following the birth of her second child.

"I immediately just felt more like myself," she told CBS News. "It's going to save so many women and families."

The drug will need to clear a 90-day Drug Enforcement Administration scheduling process, the companies said, before it can enter the market. 

The companies have not yet said how much the new drug will cost, The Associated Press reported.

Not approved for major depression

The companies had touted the once-daily pill, intended to be taken over only two weeks, as part of a potential new "paradigm" for how major depression might soon be treated. They sought FDA approval for it to treat both postpartum depression and major depressive disorder. 

However, with Friday's decision, the FDA only formally approved the drug for postpartum depression.

While doctors generally are able to prescribe treatments for unapproved "off-label" reasons, the lack of an approval restricts drugmakers from marketing the pills for those uses.

In a release, the drugmakers said the FDA told them they "did not provide substantial evidence of effectiveness to support the approval of zuranolone" for treating major depressive disorder and that more research would be needed.

In a recent clinical trial, researchers said a 14-day course of zuranolone pills appeared to help stave off further depressive episodes in many patients for months before another round of the medication might need to be taken. 

That is different from many common antidepressants, like selective serotonin reuptake inhibitors or SSRIs, which take longer to yield effects and that many patients can end up taking for a lifetime.

But those findings followed earlier setbacks for the company back in 2019, after the drugmakers disclosed a key Phase 3 study of the treatment fell short of its goal to outperform a placebo in "a statistically significant reduction" for treating depression. 

At the time, Sage Therapeutics said their data found some patients in the study had no measurable drug concentration in their body, suggesting they had missed their doses and muddied the results.  

"We see a consistent improvement in depressive symptoms associated with zuranolone, over that of placebo. Specifically, five out of six of these placebo controlled clinical studies resulted in a statistically significant improvement in depressive symptoms," Dr. Maha Radhakrishnan, Biogen's chief medical officer, had said in a December call outlining their plans to market the drug for both approaches. 

–Roxana Saberi contributed to this report.

Alexander Tin

CBS News reporter covering public health and the pandemic.