The association is linked to a common parasite that can lurk in a cat's litter box.
Researchers say the toxoplasma gondii parasite may cause undetected brain changes in women that make them more prone to mental health problems.
The parasite can also be found in undercooked meat or unwashed vegetables.
Scientists have long known a toxoplasmosis infection can be very dangerous to unborn babies, but this new study of more than 45,000 women shows changes in their own brains after being infected.
