Cat Ownership and Schizophrenia-Related Risks
A recent analysis of 17 studies suggests that owning a cat may be associated with a higher risk of conditions related to schizophrenia. This idea dates back to a 1995 study that linked cat ownership to schizophrenia, raising concerns about a parasite known as Toxoplasma gondii.
However, the body of research on this topic has provided mixed findings over the years. The 2023 review reported a notable connection between general cat ownership and an elevated risk of schizophrenia-related disorders.
Led by psychiatrist John McGrath from the Queensland Center for Mental Health Research in Australia, the team examined publications from the past 44 years across 11 countries, including the US and the UK. They stress the necessity for further high-quality studies in this area.
Some studies indicate that exposure to cats during childhood could increase the likelihood of developing schizophrenia, although not every piece of research supports this view. In fact, one study found no significant relationship between early cat ownership and later schizophrenia diagnosis, although they did identify a connection when looking specifically at ages 9 to 12.
On another note, certain papers link cat exposure with higher scores on measures associated with schizophrenia traits and psychotic experiences. Yet, it’s important to note that not all investigations show such a correlation.
In their review, McGrath and colleagues point out that 15 of the 17 studies reviewed were case-control studies, which don’t necessarily establish cause and effect. These studies often overlook other influencing factors that could skew results. Furthermore, some of the studies had low quality, and inconsistencies were noted throughout the findings.
The T. gondii parasite, which can be contracted through undercooked meat or contaminated water, as well as from an infected cat’s feces, is primarily harmless. However, it can have various effects once it enters the human body, potentially altering neurotransmitter activity and even influencing personality traits.
Estimates suggest that about 40 million people in the US carry T. gondii without showing any symptoms. Researchers continue to uncover strange effects linked with such infections, including associations with personality changes and some neurological disorders, such as schizophrenia.
The Australian team highlighted that, after adjusting for various factors, individuals exposed to cats were approximately twice as likely to develop schizophrenia. However, this finding doesn’t definitively prove causation or imply that cats are a direct source of the parasite.
It’s noted that a study involving psychology students in the US found no connection between cat ownership and scores related to schizotypy, although participants who had been bitten by a cat did show higher scores. Another investigation hinted that other pathogens might be responsible for these higher scores instead.
In conclusion, while the 2023 review supports a potential association between cat ownership and schizophrenia-related disorders, the researchers assert the urgent need for comprehensive and methodologically sound studies based on larger, more representative samples. The research findings were published in the Schizophrenia Bulletin.
