Parasite Induces Suicide in People

[jimmydasaint]

It indicates that suicide victims often show the presence of T gondii, a parasite protoctistan organism (with several warm blooded hosts, especially the cat). T gondii can cause cell inflammation which then releases metabolites which can cause inflammation of brain tissues. People with inflammation in the brain are often seen to have committed suicide, presumably after autopsy evidence.

 

Previous research has found signs of inflammation in the brains of suicide victims and people battling depression, and there also are previous reports linking Toxoplasma gondii to suicide attempts," she said. "In our study we found that if you are positive for the parasite, you are seven times more likely to attempt suicide."

 

The work by Brundin and colleagues is the first to measure scores on a suicide assessment scale from people infected with the parasite, some of whom had attempted suicide.

 

The results found those infected with T. gondii scored significantly higher on the scale, indicative of a more severe disease and greater risk for future suicide attempts. However, Brundin stresses the majority of those infected with the parasite will not attempt suicide: "Some individuals may for some reason be more susceptible to develop symptoms," she said.

 

"Suicide is major health problem," said Brundin, noting the 36,909 deaths in 2009 in America, or one every 14 minutes. "It is estimated 90 percent of people who attempt suicide have a diagnosed psychiatric disorder. If we could identify those people infected with this parasite, it could help us predict who is at a higher risk."

 

Science Daily

 

Although this is interesting news and is also interesting science, are the premises strong enough for the conclusion are are they weak enough for other factors to be considered?

 

Any comments?

[akh]

It indicates that suicide victims often show the presence of T gondii, a parasite protoctistan organism (with several warm blooded hosts, especially the cat). T gondii can cause cell inflammation which then releases metabolites which can cause inflammation of brain tissues. People with inflammation in the brain are often seen to have committed suicide, presumably after autopsy evidence.

 

 

Science Daily

 

Although this is interesting news and is also interesting science, are the premises strong enough for the conclusion are are they weak enough for other factors to be considered?

 

Any comments?

 

I am not sure of the validity of this report, but I suspect that it may be true. T. gondii has been shown to be linked to mental problems in both humans and animals. It has been linked to schizophrenia and bipolar in humans http://www.scienceda...90311085151.htm and has been shown to alter the brains of rodents http://www.scienceda...11104102125.htm. The rodent study is interesting because it appears that T gondii has evolved to manipulate the brains of rodents so they are less fearful of cats. Theses rodents are then easier prey for cats. The cats eat the rodents and become infected. People usually pick up the parasite from cat feces.

 

I used to work with a veterinarian who was a little irrational and unstable. We used to joke that she must be infected with something. Turns out that when she got pregnant, she had bloodwork done, and she tested positive for T. gondii anitbodies.

Edited August 17, 2012 by akh

[Appolinaria]

I wonder how one's immune system affects likelihood of infection from the parasite, not just susceptibility to toxoplasmosis.

[CharonY]

While toxoplasmosis may cause behavioral changes one has to add that it is also very widespread. As such associations with certain factors may easily occur by chance, especially when we look at incidents that occur with low frequency, anyway.

 

That being said, infections can very well have effect on mental states, however stating that the parasite induces it is a bit of a stretch (and I do not think that it was in the article, either).

Edited August 18, 2012 by CharonY

[Appolinaria]

That being said, infections can very well have effect on mental states, however stating that the parasite induces it is a bit of a stretch (and I do not think that it was in the article, either).

 

Stating that T. Gondii induces toxoplasmosis is a bit of a stretch? I was under the impression that anyone infected with the parasite has toxoplasmosis, symptomatic or asymptomatic.

[CharonY]

I was referring to the OP. "Induces suicide".

[Appolinaria]

That's what the article is about.

[Genecks]

Hmm....

 

Well, it opens a branch of research toward examining suicidal individuals with the infection.

But then again, it could be involved with other stuff.

 

Let's say a female is one of those bipolar, over-emotional cat ladies by her natural neurobiology.

She's kind of suicidal, but not so much.

She gets infected by the parasite and it brings her overboard.

 

I would not say the infection is a main cause, but it might be considerable to say it lowers suicide inhibitions.

I suspect it would be prime for a DOD grant.

 

My view seems to relate to this article:

J Nerv Ment Dis. 2009 Dec;197(12):905-8.

Toxoplasma gondii antibody titers and history of suicide attempts in patients with recurrent mood disorders.

Edited August 18, 2012 by Genecks

[Appolinaria]

Is it possible that people with "psychiatric disorders" are just more likely to be infected with the parasite? If a person with a "psychiatric disorder" and someone without a "psychiatric disorder" both ingest undercooked meat with the parasite, will this have any bearing on the likelihood of the parasite entering the bloodstream? I have no idea how these things work :/

Edited August 18, 2012 by Appolinaria

[CharonY]

That's what the article is about.

 

You are missing the point.

 

Stating that T. Gondii induces toxoplasmosis is a bit of a stretch? I was under the impression that anyone infected with the parasite has toxoplasmosis, symptomatic or asymptomatic.

 

The stretch was that toxoplasmosis directly induces suicide. Not that the parasite is the causative agent of toxoplasmosis. The article only shows a certain correlation that may or may not be causative in nature.

[John Cuthber]

It also increases the rate of vehicle accidents.

http://www.biomedcentral.com/1471-2334/9/72

Perhaps we should start taking it seriously.

[CharonY]

I also remember another study linking toxoplasmosis to higher risk behavior (though I do not think it was with humans). However, infections in general and other issues (including hormonal, as e.g. thyroid) also affect behavior, reaction and mood. It would be interesting to make whole immune profiles and see how many associations are found (and whether toxoplasmosis is in any regard special or not).

[ecoli]

I also remember another study linking toxoplasmosis to higher risk behavior (though I do not think it was with humans).

 

That was a study on mice and lactobacillus.

[CharonY]

Now that I think about it I think it was a study with either mice or rats with cat predation.

 

Edit: There are actually a whole bunch of papers out there with rats (a couple of papers from Berdoy et al and Webster et al, for instance).

Edited August 20, 2012 by CharonY

[John Cuthber]

That was a study on mice and lactobacillus.

Funny looking lactobacillus

http://www.newscientist.com/article/mg19425985.200-how-to-give-a-rat-a-death-wish.html

[ecoli]

Funny looking lactobacillus

http://www.newscientist.com/article/mg19425985.200-how-to-give-a-rat-a-death-wish.html

 

I was thinking of this study: http://blogs.discovermagazine.com/notrocketscience/2011/08/29/from-guts-to-brains-%E2%80%93-eating-probiotic-bacteria-changes-behaviour-in-mice/

[w0rld]

I must ask any professional on the subject, who will probably on this thread, is there any chance of this bacteria being weaponized? A suicide inducing weapon would most certainly be a very dangerous possibility.

[CharonY]

Toxoplasma is a protozoa, not a bacterium. And my point earlier is that they do not precisely induce suicide. They are just associated with it according to the studies. 20-50% of the population has toxoplasmosis if they really induced suicide most would be dead by now. Also, for the same reasons I could probably claim that cats induce suicide (as they are the primary hosts).

[Joman122]

I must ask any professional on the subject, who will probably on this thread, is there any chance of this bacteria being weaponized? A suicide inducing weapon would most certainly be a very dangerous possibility.

 

inb4terroristsreadthis

 

It would be an effective idea for sure

Edited August 25, 2012 by Joman122

[Dekan]

I must ask any professional on the subject, who will probably on this thread, is there any chance of this bacteria being weaponized? A suicide inducing weapon would most certainly be a very dangerous possibility.

 

There are certainly very attractive military possibilities here. Bacterial-weaponisation offers the benefits of large-scale population destruction in an enemy country, with no cost to ourselves - our own population will have been safely vaccinated.

 

We'll have to be careful, though, that mass application of such a weapon, by armies in the field, doesn't rebound on us. For instance, suppose our military labs develop a bacterium which induces the desire to commit fast suicide in anyone infected by it. Then we spray these bacteria over enemy troops - in the expectation that once infected, they'll all speedily shoot themselves.

 

But they might not do that - they might give expression to their suicidal tendencies in another way - by fearlessly charging at us, in a last death and glory attack - heedless of their own casualities! This could well result in them overwhelming our troops and winning the battle. We obviously don't want that - turning every enemy soldier into a "kamikaze" warrior would hardly be to our advantage.

 

Are there other ways in which the suicide-bacillus could be profitably employed?

[CharonY]

In my opinion any further discussion down that route should be held in the speculations forum.