A new long-term study reveals that exposure to toxoplasma, a disease commonly carried by cats, may increase the likelihood of psychosis in predisposed young people.

Dr. Paul Amminger of Orygen’s Personal Assessment and Crisis Evaluation Clinic studied ninety six clients aged fifteen to thirty, and found a three point six fold increase in the risk of psychosis for individuals who had grown up or lived with cats. 

Those who developed psychosis commonly had higher Toxoplasma antibody levels, which had arisen from exposure to the disease.