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In the days after Shea Oakes gave birth to her first daughter 15 years ago, she could not stop weeping. Oakes’ OB-GYN told her to let her know if she was not feeling better in three days. She wasn’t, so her doctor diagnosed her with postpartum depression and wrote a prescription for an SSRI, the most commonly prescribed class of antidepressant, on the spot.

But SSRIs can take weeks or even months to kick in, and in the meantime Oakes was in despair.

“One of the most vivid memories I have from that time was sitting in my husband’s lap while he sat in the glider rocking me,” recalled Oakes, who is now 47.

“I was just sobbing,” she said. “All the family had come and gone, my husband was going back to work, and I remember saying to him, ‘Everyone gets to leave here but me. I’m stuck with her.’”

In many ways, Oakes’ experience is a postpartum depression treatment success story. Her symptoms were obvious. Her doctor immediately recognized them, and got her treatment right away. Yet she still had to wait before feeling any kind of relief from the depression that was pulling her under.

And situations like Oakes’ are what make the U.S. Food and Drug Administration’s approval of the first-ever drug targeted at treating postpartum depression so exciting to providers who focus on perinatal mental health.

Results from trials of the drug brexanolone — which will be marketed under the brand name Zulresso — suggest it can help relieve symptoms of severe postpartum depression in two and a half days.

According to the most conservative estimates, about 1 in 9 women experience symptoms of postpartum depression. Within that, a smaller group of women develop severe depression. The risks of not treating it are clear: Though rare, suicide is the second-leading cause of death in the postpartum period.

“There are severe cases of postpartum depression where someone needs to be hospitalized, and where we’d otherwise have to wait for treatments to kick in,” Dr. Catherine Birndorf, co-founder of The Motherhood Center of New York and author of What No One Tells You: A Guide To Your Emotions From Pregnancy To Motherhood, told HuffPost. “This is potentially a really exciting option for rapid treatment [in those cases].”

Zulresso targets postpartum depression in a completely different way than SSRIs, which work by boosting levels of serotonin in the brain. Zulresso, by contrast, uses a novel neurosteroid created specifically to target the brain’s GABAA receptors, which help send chemical messages in the brain.

“One of the reasons this particular drug is so exciting is because it appears to really work with what we know happens in a woman’s body with hormones, and the drop in progesterone, and those pieces,” Kate Kripke, a clinical social worker and the founder of the Postpartum Wellness Center in Boulder, Colorado, told HuffPost. “The idea that there is the potential for this medicine that is so specific, and seemingly so accurate, is exciting.”

There are, however, serious practical questions about what kind of access women will have to the drug.

It will be administered to patients intravenously over two and a half days, requiring that they stay in a certified health care facility — and that they be watched during any interactions they have with their children during that time.

It is also expensive. The drug’s developer, Sage Therapeutics, has put its list price at between $20,000 and $35,000 for the two-day treatment.

“We want all women to have access to treatment, not just women who can afford to pay for treatment, and I think Sage would agree with that,” Kripke said — adding that for most women, medication is only a part of the treatment needed for postpartum depression, which includes therapy, support at home, sleep, and so on.

Sage recently announced positive results from a Stage 3 trial of a once-daily pill, SAGE 217, that it hopes to bring to market and that would potentially address questions about time, access, and cost. In an interview prior to Zulresso’s approval, Sage’s chief executive officer Jeff Jonas told HuffPost the company was dedicated to ensuring access to the drug, and to “clarifying” the route to treatment.

Birndorf and Kripke both cautioned that there are still questions about the drug’s long-term efficacy, as well as any long-term effects that are unknown so far. At this point, researchers have studied the drug’s impact only for the first month after treatment.

But at a broad level, perinatal mental health experts say the drug draws much-needed attention to postpartum depression, which has emerged from the shadows in the last two decades, but still needs greater visibility.