Study Finds Link Between Cat Ownership and Schizophrenia

An odd and long-posited connection between cat ownership and schizophrenia symptoms just got a boost from the scientific community.

Research published in the Schizophrenia Bulletin journal examined past studies that have found mysterious ties between having a cat and possibly developing symptoms of schizophrenia down the line. 

"It has been proposed that cat ownership may be a risk-modifying factor for schizophrenia-related disorders and psychotic-like experiences. This study aimed to systematically review and meta-analyze publications that reported the relationship between cat ownership and schizophrenia-related outcomes," the authors wrote. 

To reach their conclusions, the team looked for research on the subject between 1980 and 2023 from around the world. They also sought to find answers beyond the potential risks of owning a cat, such as being bitten by one or coming into contact with one. The scientists narrowed down nearly 2,000 studies to 17 to reach their findings. In the end, they "found an association between broadly defined cat ownership and increased odds of developing schizophrenia-related disorders."

The studies, however, did have some shortcomings, as some of the information wasn't conclusive enough to give a definitive answer. For example, the scientists "were unable to aggregate the estimates for the [psychotic-like experience] outcomes because of the broad range of measures."

"Our findings provide support for the hypothesis that cat exposure is associated with an increased risk of broadly defined schizophrenia-related disorders; however, the findings related to [psychotic-like experiences] as an outcome are mixed," the team concluded. As a result, "There is a need for more high-quality studies in this field."

Related: Growing Up With a Dog Lowers Your Risk of Developing Schizophrenia

Cat ownership's potential ties to schizophrenia risk was first explored in depth in a 1995 study that suggested the parasite Toxoplasma gondii as a cause. Studies since then have dug into the question of whether being around cats as a child might make someone more likely to develop schizophrenia, though the varied results of these studies haven't provided a conclusive answer. Some studies have gone into how being exposed to a cat can affect certain schizophrenia-related traits such as someone's thoughts, feelings, and behaviors, though others have disproven this claim. 

T. gondii hasn't been definitively pinned as the cause for any possible psychotic behavior, but it's still not exactly a parasite you want. The creature is largely transmitted to humans through undercooked meat or contaminated water, though a bite from an infected cat or the feces of an infected cat can also transmit it. 

The CDC estimates that some 40 million Americans may be infected but usually don't show any symptoms. Despite the seemingly harmless nature, however, studies have so far found that toxoplasmosis can possibly be linked to things like changes in our physical appearance, in addition to the purported link to some mental disturbances. 

It's clear more research is needed on the topic, but the connection alone is sure to be catnip for researchers.