The cat-carried parasite is the most common in developed countries and can infect any warm-blooded species, according to the Schizophrenia Bulletin. Although most humans don't suffer any symptoms from the widespread parasite, it can cause the illness T. gondii, which is linked to weeks of flu-like symptoms, blindness and even death, CBS News reports.
Two new studies have now linked the T. gondii parasite to increased rates of mental illness in cat owners who may have had increased exposure to parasitic infection.
"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," write study authors E. Fuller Torrey of the Stanley Medical Research Institute and Dr. Robert H. Yolken of Johns Hopkins University School of Medicine.