Cat owners, beware: A parasite found in feline feces could not only make you physically sick, but also mentally so, according to new research. Cats carry a parasite known as Toxoplasma gondii, which can be passed to humans through feces. As many as 60 million Americans may carry the parasite, but those with fragile immune systems can develop toxoplasmosis—an illness that can cause miscarriages, fetal development disorders, blindness, and even death, CBS News reports. Now, new research suggests T. gondii could also cause schizophrenia and bipolar disorder. Researchers compared two studies that identified a link between owning a cat as a child and the development of schizophrenia in later life with the results of a 1982 questionnaire that found 50% of childhood cat owners were eventually diagnosed with a mental illness. Comparatively, 42% of people who didn’t have a cat as a child developed mental illness, reports the Toronto Sun.
The study confirmed that owning a cat early in life could boost the risk of developing schizophrenia and bipolar disorder later. "Cat ownership in childhood has now been reported in three studies to be significantly more common in families in which the child is later diagnosed with schizophrenia or another serious mental illness," the authors say. "In schizophrenia, the evidence of an association with T. gondii is overwhelming." In a separate study, researchers found a person infected with T. gondii was almost twice as likely to develop schizophrenia as others. They also found the parasite was linked to a greater risk of obsessive-compulsive disorder and addiction, reports Medical News Today. To protect against T. gondii, don't feed your cat raw or undercooked meat, keep the litter box covered, and change the litter daily as T. gondii isn't contagious until a day after it appears in feces. Washing your hands afterward or wearing gloves will also help. Pregnant women should avoid the task entirely. (The parasite causes a surprising reaction in mice.)