If you’ve experienced postpartum/maternal depression—and 10-20% of new mothers have—you know just how crippling it can be. Now, thanks to a new study of over 8,200 women suffering from the condition in seven countries, we might have a little more insight into predicting and treating the disorder.

According to The New York Times, the study published in Lancet Psychiatry in December finds a strong link between women with the most severe form of maternal depression—including suicidal thoughts, frequent crying, and panic—and these symptoms showing up during (not after) pregnancy. These women also reported having complicated deliveries.

Meanwhile, women with less severe depression, or the more “classic postpartum,” started showing symptoms after the delivery of their babies, which might possibly be linked to post-delivery hormone fluctuations. These women were also more likely than severely depressed mothers in having complications during the pregnancy like pre-eclampsia, hypertension, and gestational diabetes, which, the Times reports, might suggest that “immune system problems might underlie their symptoms.”

The authors of this study call the report “the largest study to date on postpartum depressive symptoms,” and will follow it up with a collection of DNA from thousands of women through an international online registry, hopefully gleaning more information on how to help women predisposed to the disorder before it begins.