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Customer Discussions > Health forum

Cats can cause schizophrenia?

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Showing 1-25 of 31 posts in this discussion
Initial post: Jan 1, 2009 3:25:55 PM PST
Last edited by the author on Jan 1, 2009 3:49:33 PM PST
whitequeen says:
[Customers don't think this post adds to the discussion. Show post anyway. Show all unhelpful posts.]

In reply to an earlier post on Jan 1, 2009 5:00:41 PM PST
Oregongirl says:
Sorry, I'll pass on this one. We have enough going on here to be freaked out about without adding cats to the list. I do not say this in defense of cats. I can barely tolerate 'em, and don't own one.

I remember in the 80's when we were supposed to be all freaked about killer bees. They were supposedly heading to Oregon to wipe us all out. Well they haven't showed up yet and I STILL don't want to think about them, lol.

In reply to an earlier post on Jan 1, 2009 5:09:39 PM PST
QueenTess says:
The causes for schizophrenia are not entirely known, but experts do believe that it's mostly a genetic disease.

Schizophrenia and bipolar are not caused by viruses. As far as your relative who died, this is simply a correlated event, there is no indication of causation. I wouldn't worry about cats, but if you have relatives who were/are schizophrenic, know the early warning signs so you can be prepared to take early action with medication or treatment.

In reply to an earlier post on Jan 1, 2009 5:17:10 PM PST
Lily says:
I don't think they can. They probably just aggravate the underlying genetic predisposition that awakens scizophrenia in affected individuals.

In reply to an earlier post on Jan 1, 2009 6:18:14 PM PST
Leeta Nor says:
The CDC paper referred to here is about a possible link between the toxoplasma gondii (aka T. gondii) parasite and schizophrenia. I have heard a few bits and pieces over time about certain mental disorders such as schzophrenia and bipolar disorder possibly, at least in some cases, being caused by parasitic invasions of the brain tissue.

My opinion on that is that while unlikely to explain all cases of such, it is a very interesting theory that is well worth intensive further research.

However, (and this is largely why it is unlikely to explain all or most cases of such mental illness), toxoplasma gondii is nowhere near as common and prevalent in most normal circumstances as this paper might easily lead one to believe.

The paper further then speaks of humans becoming infected with the parasite by way of eating undercooked meat or having contact with cat feces. This is after having outlined certain dire consequences of T. gondii infection and after talling all that the parasite's lifecycle can only be completed within the body of a feline mammal (aka a cat). In other words, the parasite cannot reproduce until and unless it infects or is ingested by a feline.

Now, all that being said, the important point that I want to make here is this: T. gondii parasite is EXTREMELY RARE to be found in the feces of strictly INDOOR CATS. The cat, in oder to carry the parasite, must ingest meat of another mammal, usually a mouse or other rodent as is normal and usual cat behavior in OUTDOOR CATS.

The fear of T. gondii has for decades, caused people to rid themselves of beloved pets due to pregnancy, contraction of an autoimmune disorder, or even just aging. In most cases this was never necessary. If a cat is and has always been an indoor cat and comes from indoor cat parents, there is almost no chance of such a cat having T. gondii parasite within its system. If any part of the cat's history is unknown, a cat can easily be tested for the presence of T. gondii with a simple blood test. Should a cat test positive for T. gondii, certain antibiotics can rid the cat of the infectious parasite in most cases.

So in summary:
1. If your cat is an indoor cat from indoor parents, this should not be on your list of worries

2. If your cat goes outdoors or has unknown history, you can get the cat tested for T. gondii and find out its status.

3. Even if your cat has T.gondii parasite, so long as you do not touch or inhale the feces (as in when changing litter box with the dust flying through the air) you still would have very little to worry about.

4. If your cat has the parasite, it is a treatable problem

5. I did not yet mention this above, but the particular CDC paper referred to outlines many cases and studies done in the UK. UK countries tend to have much higher ratios of outdoor cats as pets than is found in the US. In the US, it has become generally accepted that keeping a cat indoors is the best policy for the cat's well being. In the UK, the cat's well being is generally seen as being promoted by allowing the cat to roam outdoors. Bear in mind that most statistics quoted by this article refer to the UK with its higher population of pet, or "house" cats that are not strictly limited to being indoor cats.

6. The theories presented sound plausable but are unlikely to explain all cases of certain mental illnesses

7. One more thing I've not yet mentioned: If a cat contracts the T. gondii parasite, it is only "infectious" for aproximately six weeks following initial infection. Some claim the "infectious" period is even shorter at only two to three weeks duration.

8. You stand a MUCH higher chance of coming in contact with T. gondii issues simply by eating rare meat or drinking unpasturized milk.

9. Insects such as cockroaches and flies are far more hazardous for T. gondii transmission that cats have ever been. Such insects are attracted to and feed on feces of all mammals, including of course cats, and can easily transport T. gondii on their bodies wherever they may roam. Good pest control is also much higher on the list of preventative measures against T. gondii than avoiding cats will ever be.

10. T. gondii eggs and oocysts can live quite long even without a host. Several years is the current estimate. They can be in most any outdoor area. A person may come in contact with T. gondii by working with, digging in, or playing in dirt for example. Generally this would only be a problem however if the person had skin breaks or if they were to manage to inhale some of the T. gondii. In other words, if one is going to worry about T. gondii, your first place to begin is with all your outdoor activities and the outdoor activities of your children, and not with your little cat who has never been outdoors save for on the inside of a carrier with you, for the annual vets visit.

In reply to an earlier post on Jan 1, 2009 8:19:43 PM PST
[Deleted by Amazon on Feb 9, 2010 2:44:17 PM PST]

In reply to an earlier post on Jan 1, 2009 8:31:30 PM PST
Michael Ward says:
WOW! I've never heard of anything so ridiculous-another permission to hate cats! I grew up in depression and was probably bi-polar as a child but never was near a cat-EVER! Now, as an adult I have cats and they, in fact, help me through my depression. I have 2 cousins whom are schizophrenic and none of them grew up around cats, just dogs. Where does this logic come from?

In reply to an earlier post on Jan 1, 2009 9:59:37 PM PST
Ah, cats now. Let's add that to the list of stuff to avoid. So far we have:

Milk and other dairy, microwaves, Splenda, agave, natural sugar, red meats, any animal product, aspartame, whole grains, vaccinations, prescription drugs, traditional health care, soy milk, television (cause it's a hallucinogen), dentists, chocolate, pillows for your toddler, corn syrup, fructose, tofu, and now cats. Have a fun stress-free life folks!

In reply to an earlier post on Jan 1, 2009 11:54:32 PM PST
whitequeen says:
Thank you, susanf24, for an intelligent discussion of this subject! Excellent info on why indoor cats are a safer bet than outdoor cats. You've convinced me that the old idea of letting cats be "free" isn't such a good one.

I'm surprised by how many people got upset by this topic; it was only meant "for your consideration." I grew up with cats, and I'm not a cat-hater. I happened to read in a psychiatry newsletter about a study conducted by the military at Walter Reed hospital about this very subject. For those of you who think this is ludicrous, here's the link and some of the info:

"A report on the study, conducted among U.S. military personnel by researchers from Walter Reed Army Institute of Research and Johns Hopkins Children's Center appears in the January issue of the American Journal of Psychiatry.

"Our findings reveal the strongest association we've seen yet between infection with this very common parasite and the subsequent development of schizophrenia," says Robert Yolken, M. D., a neurovirologist at Hopkins Children's who was among those conducting the analysis.

Previous studies have reported on the link between schizophrenia and the presence of toxoplasma antibodies, which are evidence of past infection, but this is the first study to show that infection with the parasite can precede the initial onset of symptoms and subsequent diagnosis with schizophrenia, Yolken says.

Because the U.S. military routinely tests its active personnel for toxoplasma, among other infectious agents, and stores blood samples in a central repository, researchers were able to determine the time line between infection and a diagnosis of schizophrenia.

"Until now, the only thing we could say is that some people with schizophrenia also had been infected with toxoplasma at some point, but we couldn't tease out which came first," Yolken says. "With our current study, we were able to show that infection came first."

While most people infected with toxoplasma never develop schizophrenia, the parasite may be a trigger in those genetically predisposed to the disorder, a classic example of how genes and environment come together in the development of disease, Yolken says."

In reply to an earlier post on Jan 2, 2009 6:44:48 AM PST
[Deleted by Amazon on Sep 25, 2015 1:11:05 PM PDT]

In reply to an earlier post on Jan 2, 2009 6:48:54 AM PST
[Deleted by Amazon on Sep 25, 2015 1:11:05 PM PDT]

In reply to an earlier post on Jan 2, 2009 8:02:48 PM PST
Mark Yannone says:
"Cats can cause schizophrenia?"



In reply to an earlier post on Jan 3, 2009 12:19:23 AM PST
Hitch says:

Actually, to the best of my knowledge, that's a misconception aided and abetted by Howard's movie about John Nash. Nash was never able to successfully discontinue his medication, and IIRC, continues it to this day. Howard even put a coda in his DVD release of the film talking about how they "fudged" on this wee bit of information.

Nonetheless, to get back on topic, I'm pretty damned sure cats don't cause schizophrenia. Susan F24's well written piece above, on toxoplasmosis (and the misconceptions that have surrounded it for ages) sums it up nicely. Virtually every bi-polar I know has it in their family, some to an amazing extent; and curiously enough, the schizophrenia I've seen personally seems to have been significantly exacerbated or brought on by serious drug use. The latter is simply anecdotal, but factually accurate, in the cases I've known.

In reply to an earlier post on Jan 3, 2009 1:55:55 AM PST
I used to work in nursing homes and as therapy we used to bring cats into the elderly. They are wonderfully therepudic. I have two of my own and now that I live alone they make me so very happy. What a stupid study and a stupid waste of money. If you believe this there is a bridge in New York I would like to interest you in.

In reply to an earlier post on Jan 3, 2009 3:03:35 PM PST
whitequeen says:
Wow! I am disheartened by the knee-jerk reaction to these studies. I'm not saying you should believe them, but merely opened the subject for conversation. Instead, I get insults and overreaction ("another permission to hate cats!"). It's obvious from what many of you said that you didn't read ANY of the information or check out the links provided. People with a scientific bent of mind consider ALL evidence, then weigh in with a considered opinion.

Doctors are realizing more and more that "genetic susceptibility" plays a bigger part in our lives than we realized. For example, think of the people who smoke 1 or 2 packs a day all their lives, and yet never get lung cancer and live to a ripe old age. Then you have people who smoked for 1 year, or never smoked, yet they end up with lung cancer. Something in their bodies made them more susceptible to outside (or "environmental") influences. Some people can eat high-fat diets with no problem, others cannot. PERHAPS it is this way with cat viruses affecting people's mental health.

We don't know everything in this world. People used to scoff at the idea of "germs," and the Western world thought gorillas were just a myth until the early 20th century! Remember, everyone "knew" the world was flat, and that the sun circled the earth. Intellectual curiosity is paramount if we're going to learn new things and deal with the problems of today.

In reply to an earlier post on Jun 17, 2012 4:32:03 AM PDT
Last edited by the author on Jun 17, 2012 4:32:41 AM PDT
OldAmazonian says:
Companionship of cats and other pets can help soothe the pain of traumatic events in the lives of young people, so cats may keep them healthier mentally and physically than they might otherwise become:

In reply to an earlier post on Jun 17, 2012 5:56:37 AM PDT
OldAmazonian says:
Perhaps it is this way with any of several viruses, including herpes, affecting mental health. Doesn't schizophrenia most commonly first become symptomatic around the same age that kids might receive initial exposure to herpes?

Posted on Jun 17, 2012 7:20:01 AM PDT
Last edited by the author on Jun 17, 2012 7:24:13 AM PDT
whitequeen says:
OldAmazonian, I agree that it's possible that various viruses could affect mental health. Your theory about herpes is an interesting one. The only reason I mentioned cats is because of the study on military personnel by Walter Reed Hospital. They took complete health histories and blood panels, even storing the blood for further testing afterwards. When people exhibited symptoms of schizophrenia, they combed thru the histories and blood panels to find a shared link. Toxoplasmosis, contracted sometime before the onset of schizophrenia, was that link. I don't know why people find this so hard to believe. After all, syphilis has been linked to insanity at a late stage of the infection.

It appears that there are probably several causes of schizophrenia, with a genetic predisposition being a strong one. I've also seen studies that "social victimization" (meaning the experience of being bullied continuously or made a social pariah) can be a factor. One study showed how immigrants who came to the U.S. in adolescence and landed in a place where they were treated with hostility and had little emotional support were more likely to develop schizophrenia. This study came out shortly after the Virginia Tech shooting by Seung Hui Cho, who had symptoms of schizophrenia and fit the profile. While this certainly made the study topical. I didn't delve into it deeply enough to know how strong its data was.

Here is a link to an interesting article on this subject, including way to lessen the chances of someone who is vulnerable developing it.

In reply to an earlier post on Jun 17, 2012 8:14:23 AM PDT
ella-catt says:
thank god someone knows what their talking about for once! nothing like facts to straighten a person with fiction to read. thanks leeta. you rock!

In reply to an earlier post on Jun 17, 2012 10:21:43 AM PDT
OldAmazonian says:
So "Yin-Lai Chang" = "leeta"?
Interesting, as is the correlation between sza and infection, but proving cause/effect may be not so simple.

In reply to an earlier post on Jun 17, 2012 10:51:08 AM PDT
whitequeen says:
OldAmazonian, I'm flattered that you thought ella-cat was referring to me. But there is a Leeta Nor who made some scientific and interesting comments in the 5th post on this thread. Now I have a question for you - how did you extrapolate Yin-Lai Chang from my "handle" here, C. Lai? (Actually, that is my former husband's name; I opened the Amazon account for him years ago and have always just used it [and my credit card], as he never buys on-line.)

In reply to an earlier post on Jun 17, 2012 11:17:01 AM PDT
OldAmazonian says:
Your former husband's name appears on the page for the Wish List in your profile. Without making the practice unmistakably clear to customers who might prefer more privacy, Amazon has for years displayed account information this way. I deleted our own Wish List some time ago for this very reason when I first noticed the problem.

Posted on Jun 17, 2012 11:19:26 AM PDT
OldAmazonian says:
Toxoplasma gondii, found in 10-20 per cent of the UK's population, directly affects the production of dopamine.

...the research team found that the parasite causes production and release of many times the normal amount of dopamine in infected brain cells.

"Humans are accidental hosts to T. gondii and the parasite could end up anywhere in the brain, so human symptoms of toxoplasmosis infection may depend on where parasite ends up. This may explain the observed statistical link between incidences of schizophrenia and toxoplasmosis infection."

"The parasite infects the brain by forming a cyst within its cells and produces an enzyme called tyrosine hydroxylase, which is needed to make dopamine.* Dopamine's role in mood, sociability, attention, motivation and sleep patterns are well documented and schizophrenia has long been associated with dopamine, which is the target of all current schizophrenia drugs on the market."

"The enzyme tyrosine hydroxylase is a crucial step in making L-DOPA (prescribed as levodopa for Parkinson's Disease), a chemical that is readily converted to the neurotransmitter dopamine."

* This seems to imply the possibility that T. gondii infection might be therapeutic for Parkinson's patients!

In reply to an earlier post on Jun 17, 2012 11:40:09 AM PDT
whitequeen says:
Wow, lots of information there - thanks! First of all, 10 - 20% of the UK's population being infected with toxoplasma gondii; that is significantly higher than in the US. This may be from their diet, as pork, lamb, and mutton are important sources of T gondii infection, in addition to "outdoor cats."

I really like your idea of being able to use T. gondii infection therapeutically for Parkinson's patients. I hope they can actually do it!

Finally, thanks for the info on the Wishlist. I've changed the settings now in order to protect my privacy.

Posted on Jun 17, 2012 12:26:56 PM PDT
Last edited by the author on Jun 17, 2012 12:34:33 PM PDT
Brian says:
The way this topic is started is rather misfortunate and leads one to not take it seriously. Then, add a bit of misinformation to it, such as the reply by Leeta Nor, and you get a completely wrong picture.

I will not go into details to prove anything (considering most have their mind made up). I will only say that these points have been proven in independent, well reviewed studies:

- T. Gondii is much more prevelant than is generaly believed. For example, up to 90% of women in some European cities are infected with it. Considering that it can stay dormant in human brain for decades, this is not surprising. However, even when dormant, it does affect human behavior.
- T. Gondii is famous for altering behavior - mice who are infected with it loose their fear of cats for instance.
- All individiuals who are infected by it show behavioral changes, which are usually atributed to personality traits. However, closer investigation reveals important and predictable differences between infected and uninfected individuals. More specifically, "lower" urges are more pronounced in those who are infected; also women who are infected appear more attractive to males. From evolutionary standpoint, this makes perfect sense as it helps the parasite propagate.
- Schizophrenia is more common among people who have cats or whose mothers were exposed to cats during or before pregnancy.
- Schizophrenia is more common among babies born to mothers who were exposed to flu viruses (may or may not be related to T. gondii)

Last but not least, claims of any infection not being very common should be taken with great dose of suspicion as there are no perfect tests for anything (although the opposite is true when there is a hidden agenda behind the bad news about some terrible infection about to wipe out the humankind - avian flu virus comes to mind as an example). Even PCR test results can be wrong. This is best proven by the fact that there has never been a disease which shrank in its distribution after better tests were introduced; in essence, the better the tests get to be over time, the more prevelant the infection becomes (due to more positive test results because of more accurate tests).
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Discussion in:  Health forum
Participants:  18
Total posts:  31
Initial post:  Jan 1, 2009
Latest post:  Jun 17, 2012

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