As if getting pelvic cysts and potentially struggling with fertility weren't enough, women with polycystic ovary syndrome (PCOS) are also at a higher risk of developing anxiety. Now, a new study suggests how all of these things might be linked. For the study, published today in the Proceedings of the National Academy of Sciences, researchers exposed pregnant rats and their fetuses to testosterone, which mimics the effects of PCOS in humans. As the researchers expected, these rats' offspring showed more anxious behavior — they were more reluctant to venture into the unprotected open arms of a maze — than those rats that hadn't gotten the testosterone treatment. To dive deeper into this connection, researchers further tested how hormones and receptors could be involved: Some rats were treated with flutamide, which prevents testosterone from activating its receptors in the brain, and others received tamoxifen, which blocks estrogen receptors. After getting doses of these drugs, the rats didn't show the same increased anxiety as the groups that only got testosterone. This suggests that the hormones and receptors that play a role in anxiety are similar to those that affect PCOS. Although this study was done with rats, we've seen similar connections in humans: Up to two in 10 women in the U.S. have PCOS, and about 60% of them also show symptoms of anxiety, depression, or another mental illness. Although we don't know what causes PCOS, we do know that it involves our hormones being out of whack and causing things such as intense pelvic pain, facial hair, and infertility. Scientists are still learning a lot about the link between PCOS and mental illness, but there's already a wealth of other research showing just how connected our moods and anxiety are to our hormones. Hopefully, the researchers can use this to find a way to treat both the physical symptoms of PCOS and the anxiety or depression that can come with them — because having PCOS is hard enough without this extra mental-health burden.