UK Study Looks at Link Between Cats and Mental Illness

Posted On: 03-31-2017

Although the cat was revered in ancient Egypt because of its ability to effectively rid a home, field, or temple of vermin, the domestic cat has more recently been derided as a source of mental illness. As recently as the 2000s, many people assumed that a common parasite that infects cats, Toxoplasma gondii, could cause the cat's owner to become mentally ill.

A study at the University College London, in the United Kingdom, reviewed the health records of more than 5,000 people as a retrospective cohort study. The peoples' charts were reviewed for cat ownership and diagnosis of a mental illness such as schizophrenia, psychosis, and bipolar disorder. The study looked at children born in the 1990s and observed them as they reached adulthood. The signs and diagnoses of the mental illnesses studied by the British researchers are typically noted during the teenage years.

Toxoplasma Gondii

The Toxoplasma gondii is present in the feces of cats. Researchers found that when mice or rats are exposed to Toxoplasma gondii, they lose their innate fear of the odor of cat urine. The parasite travels to the rodents' brains, where it causes changes in their behavior. When the rodents lose their fear of cat urine, they put themselves at risk for the cats to catch them. Because the parasite affected rodent behavior, past researchers had suspected that similar exposures could result in equally strange behaviors or even mental illness in people.

Results

In the United States, more than 60 million adults and children carry the parasite but do not experience any ill effects from their infections. No link between cat ownership and mental illness was found. There was a small data point at the age of 13 that piqued the researchers' interest, but they discovered that possible association was easily explained by co-factors such as household overcrowding, socio-economic status, hormones, and onset of puberty. Pregnant women should still avoid cleaning the litter box because the Toxoplasma gondii parasite can lead to fetal loss and birth defects.

What to Do

Be sure to have an adopted cat thoroughly examined and vaccinated by a veterinarian. If you are working in your yard and come across cat feces, be sure to wear gloves when disposing of it and wash your hands.

See Related Articles