March 2012 ATLANTIC MAGAZINE
How Your Cat Is Making You Crazy

Jaroslav Flegr is no kook. And yet, for years, he suspected his mind had been taken over by parasites that had invaded his brain. So the prolific biologist took his science-fiction hunch into the lab. What he’s now discovering will startle you. Could tiny organisms carried by house cats be creeping into our brains, causing everything from car wrecks to schizophrenia? A biologist’s science- fiction hunch is gaining credence and shaping the emerging science of mind- controlling parasites.

By Kathleen McAuliffe

No one would accuse Jaroslav Flegr of being a conformist. A self-described “sloppy dresser,” the 63-year-old Czech scientist has the contemplative air of someone habitually lost in thought, and his still-youthful, square-jawed face is framed by frizzy red hair that encircles his head like a ring of fire.

Certainly Flegr’s thinking is jarringly unconventional. Starting in the early 1990s, he began to suspect that a single-celled parasite in the protozoan family was subtly manipulating his personality, causing him to behave in strange, often self-destructive ways. And if it was messing with his mind, he reasoned, it was probably doing the same to others.

The parasite, which is excreted by cats in their feces, is called Toxoplasma gondii (T. gondii or Toxo for short) and is the microbe that causes toxoplasmosis—the reason pregnant women are told to avoid cats’ litter boxes. Since the 1920s, doctors have recognized that a woman who becomes infected during pregnancy can transmit the disease to the fetus, in some cases resulting in severe brain damage or death. T. gondii is also a major threat to people with weakened immunity: in the early days of the AIDS epidemic, before good antiretroviral drugs were developed, it was to blame for the dementia that afflicted many patients at the disease’s end stage. Healthy children and adults, however, usually experience nothing worse than brief flu-like symptoms before quickly fighting off the protozoan, which thereafter lies dormant inside brain cells—or at least that’s the standard medical wisdom.

But if Flegr is right, the “latent” parasite may be quietly tweaking the connections between our neurons, changing our response to frightening situations, our trust in others, how outgoing we are, and even our preference for certain scents. And that’s not all. He also believes that the organism contributes to car crashes, ѕυιcιdєs, and mental disorders such as schizophrenia. When you add up all the different ways it can harm us, says Flegr, “Toxoplasma might even kill as many people as malaria, or at least a million people a year.”



http://www.theatlantic.com/magazine/archive/2012/03/how-your-cat-is-making-you-crazy/8873/?single_page=true

Cats are good for rodents, but they should be not be in the house, imo.

I agree. I have a cat and never allow it indoors. I was never very fond of having indoor pets.

T. gondii is a parasite that I have worked with--that along with malaria, hookworm, blah, blah. I have a few alphabet degrees but that means nothing in regards to getting to Heaven as long as I get "S-T" for Saint, no? Anyhow on to the science lesson.

T. gondii is really surprisingly prevalent in the U.S.  It's estimated about 25% of people from adolescent-middle school age- to elderly have it. In other parts of the world, estimates are in 100% of the population. Telephorus is absolutely right- if you have a cat that has been exposed the outdoors it should remain outdoors. Only way to really prevent this is to not engage with cats or if your a kitty lover get it as a kitten (from birth preferably!) and NEVER have it outside. Once its outside the chances of it capturing a rodent, a mouse (those famous ones that bring the mouse to your doorstep are very suspect!)

The T. gondii way of continuing its lifecycle is in its fecal matter and anything to do with a litterbox, infected soil-infecting in vegetable gardens and even water primarily, undercooked meat, etc. So at least wash those hands folks after handling that darn litter box at the very least!! Regarding the unborn babies and telling women to not change the box is because the parasite gets through to the baby's brain by crossing the placenta then it's not protected by mother's immunity and pretty much scrambles the brain prior to birth. So it does create miscarriages, stillbirths, severely impaired neurological children, and in some cases death after birth. Those infected babies that do not show signs at birth generally show signs in 20's to 30 years of age. Mothers who are affected by the antibody of T. gondii have a very high propensity to have children who later develop schziophrenia.

One of the main issues with T. gondii infection is the risk-taking factor. This is seen with infected mammals--rats being primary here. Usually a rat will run for the hills when it smells/detects cat urine. This is simply called fear- neophobic if you want to get real technical. Now the accidental host, a human will exhibit the same type of lack of fear. As a result it is found in a recent study out a Czech Republic university that if you are infected with T. gondii you have about a 2.5 times more likely to have a car accident. The T. gondii lessens reaction time, ups the ante on risk taking in driving so you can die. Why you ask? Hmm it wants you to be ate up by it's real host--the cat. I know, I know. It's silly but don't tell that the the simple minded parasite its just trying to continue its lifecycle of cat to mouse/rat.  This same study has estimated an average of 600,000 road deaths per YEAR is a result of this infection.   This risk-taking is to be eaten by a feline- usually in our lives its the house kitty but in other times of history it wasn't unheard of to be part of bushmeat for lions, tigers- oh my!

Another way to show signs of risk taking in humans that is way more noticeable is actually more promiscuous--but generally really outgoing and warm, kind and follow authority. The guys--nah not so much. Guys with the T. gondii antibodies are just weirdos in society--the unkempt loners of the world who dislike authority.

Other ways the T. gondii affects a human is psychologically. The largest one is depression. Many of those infected have a deep depression-in fact so deep that the person wants to kill themselves. Interestingly- there are cases of people killing themselves via a big cat- either throwing themselves over the fence at a zoo or running into an area where big cats roam freely-- but that is rare but statistically valid. Most of those that experience depression and thoughts of ѕυιcιdє can be treated-- but first you have to be treated for T. gondii first and then have successful treatment of antidepressants. Those treated with the complete protocol generally have very successful outcomes of no further signs of depression 10 years out.  The other more prevalent way of psychiatric disorders is schizophrenia. This is really interesting--we we look at people who have schizophrenia we have found that upwards of 50-85% of those affected have the antibodies of T. gondii. Interestingly--those within the studies going back to the 1950's show that many of those that have schizophrenia (average of 50%) had cats in their childhood. Those affected with schizophrenia usually show symptoms of their disease by their 20's--the known latency period of those infected pre-birth with no signs of neurological damage.

Now, after having said all of this I need to say that the mice,cats, T. gondii, schizophrenia that there is no conclusive evidence, why? Well we can't tell exactly WHEN the infection occurred. It could be perinatal, postnatal, heck even if you ate some undercooked meat in your lifetime. So those seropositive for T. gondii can get it from pigs, goats, sheep heck even unpastuerized milk. So it isn't always the cat--but it seems to be a lot of those practicing a rural lifestyle that seem to be infected.

Also-note the difference between antibodies -which is the 'memory' of an infection vs. actively ill with infection of parasite.  Usually those infected have flu like symptoms versus those actively infected with the parasite. To treat the infection depends on if it's acute (active stage) or latent. Anti-malarial meds with antibiotics are the course of action.

Rather than blather on I guess I'll stop here. But I could probably write a book on the effects of infection and those have high antibodies of T. gondii.

This is....  freaking.  Me.  Out! I'm reading this as my cat is curled up in my lap sleeping. The irony.

er  :detective:

The only cats I will allow in my house is the picture of four tat hangs over the fireplace.
 

Got 2 of my own, had one when got married and one took up with us, now we are used to having 2..had one from age 5-19, the next age 24 and on.....

Got a dog, too, but to me cats are regal and intelligent, love their independant attitude...

Cats are good for rodents, but they should be not be in the house, imo.

My cats are not amused, good sir.

As for T. gondii, there have been approximately 20 studies done since 1953 regarding any correlation between infection and the exhibition of severe psychological symptoms (not just schizophrenia) and in about half there was a statistically significant greater incidence.  That said, wisconsinsheepgirl is correct in that not knowing the source or duration of infection makes that correlation of little diagnostic value.

Regarding the lack of fear of cats on the part of infected rodents, this fear is the result of successive generations of great selective pressure that have been expressed because the predisposition to such fear has led to greater survivability.  There are, however, several mechanisms not directly related to mental illness that can be used to explain this lack of fear.   It is known that cysts of T. gondii invade both the amygdala (which among other things provides emotional valence to fear/flight responses) and olfaction centers of rodents, and also in the nucleus accuмbens, which processes reward response via dopamine.  It's not inconceivable that such dopaminergic overabundance would blunt a fear response.