Past studies have linked the parasite, Toxoplasma gondii - found in cats - to symptoms of psychosis in humans. These studies suggested that kids who grow up with felines are more likely to develop mental health issues. Much to the relief of cat lovers, a new study casts doubt on that link, finding no such connection between cat ownership and an increased risk of psychosis.
"The message for cat owners is clear: There is no evidence that cats pose a risk to children's mental health," study lead author Francesca Solmi, a researcher in the Division of Psychiatry at University College London (UCL), said in a statement released by UCL.
The Toxoplasma gondii parasite has been associated with the development of schizophrenia and symptoms of psychosis, such as hallucinations. Research published in 2015 also found the link between owning a cat in childhood and developing schizophrenia or other serious mental issues.
However, these cat studies were limited because they were small, were not rigorously designed and did not properly account for factors that could affect the link, the UCL researchers said.
In the new study, the researchers analyzed information from nearly 5,000 children who were born in England in 1991 and 1992, and followed them until they were 18 years old. The researchers looked at whether the kids' mothers owned a cat while pregnant, and whether the family owned a cat when the children were 4 and 10 years old.
The researchers also interviewed the children at ages 13 and 18, to assess whether they had experienced psychosis symptoms, including delusions, hallucinations and intrusive thoughts.
Overall, there was no link between cat ownership and symptoms of psychosis at ages 13 and 18.
Initially, the researchers did find a link between cat ownership at ages 4 and 10 and symptoms of psychosis at age 13, but this link went away once the researchers took into account other factors that could influence the results, such as the family's social class, the number of times the family moved before the child was 4 years old and the age of the child's parents.
While the researchers agreed that cat ownership doesn’t significantly increase the risk of exposure to the parasite, they caution women who are pregnant, to avoid cleaning litter boxes because the parasite can be present in cat feces.
"Our study suggests that cat ownership during pregnancy or in early childhood does not pose a direct risk for later psychotic symptoms," explains senior author Dr. James Kirkbride (UCL Psychiatry). "However, there is good evidence that T. Gondii exposure during pregnancy can lead to serious birth defects and other health problems in children. As such, we recommend that pregnant women should continue to follow advice not to handle soiled cat litter in case it contains T. Gondii."
The study was recently published in the journal Psychological Medicine.
Story sources: Rachael Rettner, http://www.livescience.com/57978-cats-psychosis.html