Owning a cat is linked to roughly double the odds of developing schizophrenia, a serious mental illness where people can lose touch with reality. Researchers at the University of Queensland went through 43 years of studies and kept finding the same link. Out of 1,915 studies published between 1980 and 2023, only 17 were good enough to make it into the review. Psychiatrist John McGrath led the work, and Schizophrenia Bulletin published it in 2024. People who had been around cats were about 2.4 times as likely to have a schizophrenia-related diagnosis, after the researchers accounted for other factors. Dropping one unusual study pulled one of their estimates down to about 1.6 times, a smaller link that still held. A parasite called Toxoplasma gondii is the main suspect. Cats can carry it, and it can reach the human brain, although this review measured cat contact only, so the parasite itself still needs testing. Fewer than 1 in 100 people develop schizophrenia, so double a small risk is still a small risk. Many of the studies also asked adults to remember whether they had a cat as a kid, and memories can be wrong. The researchers want more high-quality studies, but across 17 of them, the link kept showing up.