It is no secret that I love cats. So I have interestedly, and somewhat anxiously, followed the stories about how toxoplasma gondii, a little microbe that lives inside your cat, has been shown to make rodents lose their minds a little, and could possibly make you lose your mind a little, too. (Insert joke about crazy cat ladies here.) Two scientific studies published recently appear to confirm this hypothesis, and push it closer to the realm of FACT. Except... maybe not.
Here's the short version of the toxo story. (The long version is here, and very interesting and definitely worth reading.) Toxoplasma gondii is a parasite — a teeny, tiny, single-celled parasite that can be inside all sorts of warm-blooded mammals, but would prefer to be inside a cat, because only inside a cat can it reproduce and make more sweet little toxoplasma gondiis.
Let's say the microbe is inside a mouse. To get back inside a cat, it does something very unusual: it actually gets inside the mouse's brain and changes the way it thinks. Yes, you read that right. A toxo-infected mouse will be attracted to, rather than repulsed by, the smell of cats, which, happily for the microbe but unhappily for the mouse, will hopefully soon result in its becoming a cat snack.
Of course, you are not a mouse. And it doesn't seem particularly likely that you will be eaten by a cat, so why would a microbe want to mess with you? We're not exactly sure how it works, but the theory goes that if toxo can rewire the circuitry of a mouse or rat's brain, maybe it could do the same for you. And in fact, in studies, a Czech scientist has found subtle but significant personality differences in people infected with the bug.
More disturbingly, some scientists have began to suspect that there may be a link to between childhood exposure to toxoplasma gondii and schizophrenia. In an effort to replicate earlier studies that appeared to show a link between childhood cat ownership and schizophrenia, researchers sorted through old surveys and discovered that 50.6 percent of schizophrenics had a cat growing up, as compared to 42.6 percent of the general population.
A separate study found a significant correlation between signs of prior infection with toxoplasma gondii and schizophrenia, bipolar disorder, addiction, and obsessive-compulsive disorder. Put the two together and the evidence against our feline friends seems pretty damning. People with cats are more likely to develop schizophrenia! And cats carry toxo, which is also linked to schizophrenia! So... having a cat will make you crazy?
Except not so much.
This first study, as this excellent article on Jezebel points out, doesn't prove that having a cat as a kid causes schizophrenia, only that there could be some connection between the two. (You know, the old correlation-isn't-causation thing. Hope you paid attention in high school science.) And the second study, while it did show a link between toxoplasma gondii and certain mental illnesses, didn't concern itself with how or why the participants contracted the bug.
Sure, one way to contract toxo is by handling the feces of an infected cat (read: scooping out the litter box). But you can also get it from touching raw meat, or from contaminated vegetables or water. Even eating raw oysters will put you at risk. Most people who contract toxo don't even know it: the symptoms of an infection usually resemble a cold or the flu. Probably you'll bounce back from it, feel perfectly fine, and not even know that there's a single-celled organism in your brain that may or may not be making you crazy. The world of microbes is a terrifying place.
But anyway, we were talking about cats. Which are correlated with, but not necessarily the cause of, schizophrenia. And they carry a bug that has also been linked to schizophrenia — but that you can get from a lot of other places, too. (Also, cats can only get toxo from raw meat, so if your cat doesn't already have it and you feed him or her only canned or dried food, you're in the clear.)
So cat owner = CRAZY is far from scientific fact. And, in fact (I based this on a scientific study I did, with a sample set of myself), getting love and cuddles from your cat friend might actually help take the edge off all the other things that are threatening to drive you insane. So keep calm and cat on.
You can read more about this at Jezebel.