What if adopting a cat could make us schizophrenic?
A recent study conducted in Australia suggests that cat owners may face a higher risk of developing certain mental disorders, including schizophrenia. Let’s explore the potential mechanisms behind this surprising observation.
An Infection Transmitted by Cats
Cats are often associated with numerous health benefits: reduced stress, greater emotional stability, lower blood pressure, and even a reduced risk of cardiovascular incidents. However, a new study published in the Schizophrenia Bulletin in May 2024 challenges this positive image by linking cat ownership to an increased risk of mental disorders.
This study, conducted by the University of Queensland in Australia, highlights the role of the parasite Toxoplasma gondii in this phenomenon. Responsible for toxoplasmosis, this microorganism infects many mammals, including humans. Cats, as primary hosts, facilitate the parasite’s reproduction in their intestines before it is excreted in their feces. Thus, contact with contaminated litter can expose cat owners to this infection.
Toxoplasmosis and Psychiatric Disorders
Toxoplasmosis generally goes unnoticed in healthy individuals (or immunocompetent individuals). However, it poses significant risks for certain groups: pregnant women, immunocompromised individuals or those living with HIV, and people vulnerable to neurological conditions. In these groups, the infection can cause severe inflammation, psychiatric disorders—such as schizophrenia—as well as conditions like obsessive-compulsive disorder, bipolar disorder, and even certain addictions.
The parasite works by altering dopamine levels, a key hormone in mood regulation and cognitive functions. It can also cause neuronal damage and disrupt neurotransmitter systems. Additionally, the immune response triggered by the infection can lead to chronic inflammation, further increasing the risk of developing mental disorders.
What Risks Do Cat Owners Face?
While immunocompetent individuals are generally less affected, the risk is never completely absent. By hosting this parasite, cats indirectly become a risk factor for serious illnesses in their owners.
To mitigate these risks, it is essential to adopt good hygiene practices, such as washing hands after handling a litter box and avoiding contact with contaminated feces—especially for at-risk groups.
