Why Some Women May Be More Biologically Susceptible to Postpartum Depression

When Chrissy Teigen revealed to Glamour that she suffered from postpartum depression (PPD) after giving birth to daughter Luna, she brought yet another important women's health issue front and center. (We already *love* the supermodel for telling it like it is when it comes to topics like body positivity, the IVF process, and her diet.) And it turns out that PPD is pretty common-it impacts about 1 in 9 women in the U.S., according to the Centers for Disease Control and Prevention (CDC). And researchers estimate that only 15 percent of women who are affected get treatment. So we should be talking about it.

That's why we're stoked to see the latest research coming from Johns Hopkins University. It shows that having high levels of an anti-anxiety hormone throughout pregnancy-especially the second trimester-may protect soon-to-be-moms against PPD. What's better, though, is that these new findings could one day lead to tests and treatments that help prevent the condition. (Side note: Did you know an epidural may lower your risk of PPD?)

In the study, published in Psychoneuroendocrinology, researchers measured levels of allopregnanolone, which is a byproduct of the reproductive hormone progesterone that's known for its calming, anti-anxiety effect. They looked at 60 soon-to-be moms who had all been previously diagnosed with a mood disorder (think: major depression or bipolar disorder), and tested the women's levels in both their second and third trimesters. After the women gave birth, the researchers found that those who had lower levels of allopregnanolone during the second trimester were more likely to be diagnosed with PPD than women with higher levels of the hormone during that same time period.

"Allopregnanolone is measured in nanogram per milliliter (ng/mL), and for every additional ng/mL, a woman had a 63 percent reduction in her risk for PPD," says study author Lauren M. Osborne, M.D., assistant director of the Women's Mood Disorders Center at the Johns Hopkins University School of Medicine.

During pregnancy, both progesterone and allopregnanolone naturally rise steadily and then crash at childbirth, explains Osborne. Meanwhile, some evidence indicates that the amount of progesterone that gets broken down into allopregnanolone may decrease toward the end of a pregnancy. So it could make sense, then, that if you have lower levels of allopregnanolone floating through your system right before birth-and then experience a halt of the hormones at childbirth-that your anxiety levels could rise and make you more susceptible to PPD, of which anxiety is a common symptom. (Plus, more need-to-know facts about PPD.)

Osborne says that the research doesn't fully answer the question of why allopregnanolone is able to protect against PPD, "but we can speculate that perhaps the low levels in the second trimester are involved in a chain of events that lead to PPD-either through brain receptors, or the immune system, or some other system we haven't thought of."

She also notes that some women might simply be more susceptible to PPD because of already-low levels of allopregnanolone outside of pregnancy, as evidence shows a link between low levels of the hormone and depression. (

That said, no one's suggesting you run out for an allopregnanolone test if you have a baby on the way (though, FWIW, there is a blood test for it). After all, Osborne admits that this is a small study with preliminary results, so a lot more research needs to be completed. Plus, what has been done comes with caveats. First and foremost: This study was done with a group of high-risk women, rather than ones who didn't have any prior diagnosis of a mood disorder. Which means that they don't know yet if the same results will be found when a more general population is analyzed.

Still, it offers hope for what's to come for women's health and treatment. Osborne says she hopes to study whether allopregnanolone could be used to prevent PPD in at-risk women, and Johns Hopkins is one of a few institutions looking into allopregnanolone as a potential treatment for PPD.

So while the scientists tend to that, your best bet is to keep an eye on your mood. "Almost all women-about 80 to 90 percent-will have 'the baby blues' [and experience] mood volatility and crying in the first few days after birth," says Osborne. "But symptoms that last two weeks or more, or are more severe, could [indicate] postpartum depression."

Having trouble sleeping; feeling fatigue; excessive worry (about the baby or other things); having a lack of feelings toward the baby; appetite changes; aches and pains; feeling guilty, worthless, or hopeless; feeling irritable; having a hard time concentrating; or thinking about harming yourself or the baby are all symptoms of PPD, says Osborne. (Plus, don't miss these six subtle signs of the condition.) If you experience any of those, touch base with your doctor as soon as possible because-silver lining!-Osborne says PPD responds very well to treatment. There's also a Postpartum Support International Branch in every state for those looking for additional options.