A very recent study published online on 22 February 2017 debunks the theory that cats cause mental illness in people. This is an evergreen topic of discussion and there is conflicting information on the Internet as to whether the domestic cat causes mental illness amongst human companions because the cat is the primary host of the protozoan parasite toxoplasma gondii.
Tens of thousands of words have been written in news articles on the Internet based upon research studies which stated that schizophrenia and mental health issues in people could be caused by the domestic cat having transmitted the parasite to humans via their faeces (a zoonotic disease). The news articles have sometimes stated confidently that the world is going mad because of the domestic cat!
The truth is that although there have been no conclusive studies on this matter, the online news media created what I would call fake news of a sort which in turn led to cat haters denigrating the cat and seeking the extermination of the feral cat.
We now have a further study which I believe puts the record straight to a certain extent. It comes out of the University of London, UK.
The research is published online. You can read the summary, if you wish, by clicking on this link (it is technical). It is entitled: Curiosity killed the cat: no evidence of an association between cat ownership and psychotic symptoms at ages 13 and 18 years in a UK general population cohort.
The conclusion is that while pregnant women should be cautious about handling cat litter (I have covered that issue in previous articles – please use the custom search engine), the study “strongly indicates” that can ownership in pregnancy or during early childhood does not pose a risk to adolescents of contracting psychotic experiences (PEs).
The team who carried out the research criticise previous studies, remarking:
“Previous studies reporting links between cat ownership and psychosis simply failed to adequately control for other possible explanations.”
The way I read this is that previous studies were not carried out accurately enough in not taking into account other possible causes of psychosis or mental health. Research studies are very complicated and you need to build into the model (the method that the study is based upon) many factors which may influence the outcome of the study and which may distort its conclusions. Computer programs can do this. The researchers need to introduce these programs and methods in order to arrive at a clean result.
I’m not, by the way, necessarily supporting this particular study but it is good to see one which redresses the balance.
In this study 6,705 children age 13 and 4,676 children age 18 were examined to assess associations between cat ownership and psychotic experiences1. The adjustments were made for sociodemographic and socio-economic factors and also dog ownership and household characteristics.
To re-emphasise, Dr Francesca Solmi, the lead researcher, said that:
“Previous studies reporting links between cat ownership and psychosis simply failed to adequately control for other possible explanations. Once we controlled for factors such as household overcrowding and socio-economic status, the data showed that cats were not to blame.”
So in answer to the question in the title, “Do Cats cause mental illness?” we would have to say that this is still work in progress if we are to be completely honest even though I’m a cat lover and animal advocate. In short we don’t quite know yet but the strong indications are that cats do not cause mental illness in people.
You might also wish to look at the question from a different angle. If the cat did cause mental illness in people, primarily cat owners and family members, it would have come to light by now. We would know about it through personal experiences and masses of anecdotal evidence. In addition, I would have thought that the domestic cat would not be as popular as it is in America and all over the planet if there was the hint of a possibility that he/she made their owners mentally ill. People don’t believe the earlier studies linking cats with mental health issues.
Note 1: the researchers used data from the Avon Longitudinal Study of Parents and Children (ALSPAC).