I'm not sure how much human contact feral cats have, being feral and all, but cats that are adopted (or in my case, just took up residence) from who knows where, may be a factor.

It's not contact with the cats you should be concerned with. The parasite is spread through the cats' waste products, which, if you live in an area with alleycats like I do in Italy, you would know that cat droppings are very often found in areas where mice are found, i.e. trash cans, alleys, streets, sewers, etc.

Mariella

Fuller Torrey had noted that keeping cats indoors is a practice that proliferated in the twentieth century and he suggests that the litter box is the culprit.

[edit on 2006/8/6 by GradyPhilpott]

Thanks for the stats.

I honestly dont see a connection between cats and schitzophrenia or even evidence that half of humanity carry this virus. Or that this virus causes mental disorders and neurosis.

the litter box is the culprit

Exactly my thoughts. I'm not trying to blow this all out of proportion or anything, just presenting a topic of personal interest and looking for some answers.

You can't be too careful around fecal matter of any kind, and I have always found cat waste particularly nasty.

I'm curious about the growth in the incidence of such maladies as anxiety and depression, as well as schizophrenia, since the keeping of cats indoors, along with their litter boxes (my cat's stays outside in an enclosed breezeway) became standard practice. A corresponding rise in neuroticism during this period would be indicative that Toxoplasma could indeed be a contributing factor. Hardly conclusive, though, as there are so many other factors involved, no control group, and no empirical method applied.

It certainly wouldn't be unprecedented, to have a parasite that affects behaviour of its host organism. There is a parasite that infects ants, makes them crawl to the top of a blade of grass and stay there, this makes them more likely to be eaten by grazing cows, which are the next step in the parasite's lifecycle. There is even a parasite that infects male crabs, 'chemically castrates' them and this 'feminizes' them, they develop 'brood pouches', and act like female crabs, taking care of the brood, but the brood, its more of the parasite.

There are actually many parasites like this. Its not hard to beleive that there are some that affect humans.

I've heard this talked about for a year or two.
It is an interesting theory.

Though whenever I read about it, I think about the Goa'ould.

Originally posted by Nygdan
Consider a parasite or disease that is spread by sex. What if it took up residence within brain cells that control the sex drive, or infected glands and caused them to over-produce sex hormones, etc. That'd be a very 'good' evolutionary strategy.

Sure. If it were a human parasite. But T. gondi affects cats. There would seem to be little selective advantage to a cat parasite in making humans schizophrenic.

If a higher prevalance of human schizophrenia somehow caused cat numbers to increase, you might have a (just) plausible connection.

Frankly, it would be more credible to claim that T. gondi changed cat behaviour to make cats more attractive to humans, thereby increasing their chances of survival and reproduction and so providing more hosts for the parasite.

Leaping boldly off topic, I suggest the following.

From a human perspective, cats are parasites. They used to be symbiotes, but the hordes of toms and tabbies now infesting the urbanized world aren't there to keep their owners' barns free of mice. They are there to be stroked, played with and pampered. You might say their symbiotic functions are now psychological, but that's a tenuous line of argument to say the least -- anyway, dogs do it better.

So cats are parasites. We love 'em (at least some of us do), but that's what they are.

And like many parasites, cats affect their hosts' behaviour in ways that facilitate the cats' survival and reproduction. We know the obvious ways: playing nice to get fed, housed, groomed, etc.

But what if there are subtler ways? What if the whole of human culture is shaped, not by cat parasites, but by cats?

Now that's a thesis I find really interesting. In fact, it's what I thought this thread was about. A moggy conspiracy to shape human behaviour -- one that has resulted in the entirety of human culture (religion included, obviously).

You know, the more I think about it, the more credible it sounds. A lot more credible than blaming poor Pickle and Rubadi for my brother-in-law's mental condition.

Originally posted by Astyanax
Leaping boldly off topic, I suggest the following.

But what if there are subtler ways? What if the whole of human culture is shaped, not by cat parasites, but by cats?

Not quite as far OT as you'd think, as to an extent this is actually true.

I'd widen it a bit and say that it's the the 'domestication' of animals has shaped human culture, rather than a single species (but that's to take the humour out of your post, and looking at my cats this evening, I know that they are planning something).

Cats would seem to be an obvious choice, as where you have stock you store fodder, and where you store fodder you have mice and rats - so having small 'domestic' predators around is handy. Not sure why cats lend themselves so readily to this role, as against other predators (Ermine and their kin for example) - perhaps cats are just kinda lazy, and the barn is a controled hunting ground - much like a game reserve for them

Dogs have been with us for a long time, a very early domestication, or a partnership if you prefer, and they, like us can carry toxoplasmosis (although it only breeds in cats). Cats tho' - hmm, quite a recent thing I'd guess, especially given the rate that they seem to slip back into being feral.

Originally posted by Astyanax
Sure. If it were a human parasite. But T. gondi affects cats. There would seem to be little selective advantage to a cat parasite in making humans schizophrenic.

T.gondii infects humans.

If a higher prevalance of human schizophrenia somehow caused cat numbers to increase, you might have a (just) plausible connection.

Or if being schizo meant that you tended to forget to clean out your cat litter box, or you took in and cared for lots of cats because you're some 'crazy cat lady', etc. THe organism can invade human brain cells, that was my point, if it can do that, it doesn't have to have some sort of evolutionary advantage to cause schizophrenia, it just causes damage that happens to result in schizophrenia, or some other organiz mental disease.

Frankly, it would be more credible to claim that T. gondi changed cat behaviour

I agree. I am not trying to say that T.gondii does cause schizophrenia in humans, merely that its not so crazy as it first sounds.

ive owned cats most my life. indoors-outdoors. ive never owned a dog. im a cat guy.
i have serious issues with anxiety.... social and situational. dehibilitating... very.

my girlfriend owned cats all her life. she is a schizo.



[edit on 7-8-2006 by krossfyter]

ALL of the wierdest, most excentric friends I have own a ton of cats. Like 4+...Personally, I've met enough wierd old ladies that have 20+ cats to belive in the POSSIBILITY of a link...

Originally posted by bsl4doc
The only flaw with this idea is that half the world's population isn't infected with toxoplasma gondii. It seems that in several studies, only 30% of the population tested showed antibodies, which means they had AT ONE TIME been infected or were at that time infected. So if half of those testing positive for antibodies were infected, that's only 15% of the population.

Mariella

Thanks for that! My husband was telling me about this, and I *stared* at him and said "that's not possible! I want to see their study!" and rattled off cultures that didn't historically have cats and indeed show (for a long time) that countered the theory.

It turns out (on examining the article) that there IS no study. This is an article by a science fiction site.

It's all speculation.

Culturally, there's thousands of cultural counterexamples, and, as Mariella said, the numbers are absurd. There are many places where historically people didn't have cats (Siberia, the whole continent of America, central and southern Africa) and do have psychoses.

The writer also shows lack of understanding of the material when he seems to think that rats running to cat urine soaked areas (because of toxiplasmosis) is a survival trait. In fact, it's the opposite. Urine is a territorial marker and sooner or later the cat will come strolling around and the rat is history.

My husband tried to tell me that the toxoplasmosis also occurs in areas where there are larger felines (tigers and lions)... however, these don't eat rats. It'd be the dogs that ate the rats in that ecosystem.

You have the information backwards. The rats running to cat urine are infected with T. gondii, thus showing the aberrant behavior it causes. There are several scientists and their studies quoted. It isn't strictly speculation.

The site is about the "science of fiction", not a science fiction site. How many of the things we take for granted today were science fiction 100 years ago?

People will believe what they want to believe, and arrange the facts accordingly.

Originally posted by Icarus Rising
People will believe what they want to believe, and arrange the facts accordingly.

Unfortunately, this is true. No matter of scientific studies seem to deter some people from their basic reply of "nuh-uh".

Mariella

Very true. It is even done by those who claim to be knowledgeable professionals in their field. Go figure.

[edit on 8-8-2006 by Icarus Rising]

Originally posted by Icarus Rising
Very true. It is even done by those who claim to be knowledgeable professionals in their field. Go figure.

[edit on 8-8-2006 by Icarus Rising]

Hmm....I've yet to see a doctor who refutes a scientific study with a pop-culture article. Wait, you don't have an MD or PhD, do you?

Hehe, all in jest, I promise. An interesting discussion at least, no?

Ciao, da sveedanye, dobroi dyen =)

Mariella