Cat's out of the bag—there is a real scientific connection between owning a cat and developing schizophrenia, OCD, and other mental illnesses

By Rachael Schultz
June 10, 2015
Corbis Images

Your feline friend may make home a happier place, but her presence may also be taking a toll on your mind. Owning a cat can significantly increase your risk of developing a mental illness like bipolar disorder, schizophrenia, obsessive-compulsive disorder, or even addiction later in life thanks to a dangerous bacteria hiding in their litter box, according to two recent studies. (Need help? 8 Alternative Mental Health Therapies, Explained.)

It sounds crazy, but this isn't just a smear campaign by dog owners. T. gondii, a dangerous parasite that can live in the soil, water, or kitty litter for years, is present in the poop of cute, cuddly cats (as well as feral felines). And touching or ingesting anything that has come into contact with infected feline feces can infect you, leading to toxoplasmosis, an illness that infects 60 million Americans, according to the Centers for Disease Control and Prevention (CDC). (Read these 6 Ways to Clean Your Place Like a Germ Expert.)

A Dutch research team looked at 50 published studies and found that a T. gondii infection is associated with several psychiatric disorders, most often schizophrenia. They found this link not just soon after exposure, but also years later, particularly among young people who were exposed to T. gondii as kids. In fact, infected children are almost two times as likely to develop schizophrenia and are slightly more prone to other mental health issues, the study reports in Acta Psychiatrica Scandinavica. In addition to psychiatric disorders, T. gondii infections can also cause miscarriage, blindness, fetal development disorders among unborn babies, and death (in extreme cases), according to the CDC.

You can become infected by T. gondii from other means, like eating undercooked meat or off of utensils that have come into contact with raw meat, of course. But accidentally touching cat feces is one of the most common ways to contract toxoplasmosis.

Now, we're not asking you to kick kitty out-especially since studies have shown owning a cat can lower your risk of having a heart attack, lower your stress levels, and actually boost your immune system.

You can reduce your cat's risk for infection by keeping her inside, since the most common path of contraction is by eating infected soil or feces. Wondering if your cat is already diseased? Symptoms range from simple lethargy to a wobbly gait to vomiting, so if you're worried, talk to your vet. (Keep her as healthy as possible with The Best Health and Fitness Products for Your Pet.)

As for your own health, reduce your risk by changing the litter daily-the parasite doesn't become infectious until one to five days after a cat has done her business. And if you are pregnant or sick, avoid changing the litter yourself, the CDC strongly advises. And while no one likes for a stereotype to be proven right, when it comes to feline owners, well, the cat's out of the bag.