Professor links marijuana, schizophrenia, and brain development For boys vulnerable to schizophrenia, cannabis use may change brain structure

Dr. Tomas Paus, professor of psychology and psychiatry at the University of Toronto, has co-authored a study linking the use of marijuana among schizophrenia-prone adolescents to structural changes in the brain.

The study examines almost 1,600 subjects, some of whom did, and some of whom did not use marijuana before the age of 16. Some subjects had a high risk of schizophrenia, and some had a low risk, based on polygenic testing (testing numerous genetic locations for traits associated with schizophrenia).

The goal was to find the effect of cannabis use on the development of the cerebral cortex — the outer layer of brain tissue, which plays an important role in perception, memory, language, and consciousness in general.

Among male subjects who had a high risk of developing schizophrenia, those who used cannabis during adolescence developed significantly thinner cerebral cortices than those who didn’t, and the more often a subject used cannabis, the more pronounced the effect was. But males with a low risk of schizophrenia saw no change to their cerebral development as a result of cannabis use, and females at either high or low risk were likewise unaffected.

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I’m sure this is what happened to my son. He has the gene and he began smoking I’m not even sure when, but he started having some symptoms, or he started changing a little bit around 17. It was gradual at first and then suddenly BOOM! He still smokes pot.

I would like to blame the drugs, but it seems less likely as time goes by.

I’m sure marijuana/skunk weed messed my brain up, but I wonder if salvia did more damage as it is stronger.

I would like to see more research done with salvia.

From the research I did back in the day, they said salvia didn’t do any permanent damage to the brain, in comparisson to other drugs like lsd for example.

I didn’t know lsd damaged the brain. I just assumed it made one more introspective and creative. I won’t try it though because I’m mentally ill. Have you tried it? My friend tried it. I believe it benefited him.

I tried it, and I abused it. It’s an instrospective and creative drug, you’re right. It used to be my favorite drug, until my psychosis blew while I was high and then no more of it.
Lsd not only damages the brain, its molecules attach to your fat and when you burn the fat you have a risk of what they call a flashback and you get high again. I’m rather scared about those flashbacks, I really don’t want that to happen to me.

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This study is correlational and does not indicate a causal link.

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Have you heard about that study that concluded that global warming was caused by less pirates being around?

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Yeah, lol. That’s a funny one.
Honestly though, I think it’s a problem that correlational studies on drug use are given too much attention. By the press and the public, I mean. Also many doctors that I’ve talked with. (Attention is good as long as everyone understands what they’re reading.)

Isn’t it easier to show correlation than causation though?

Showing causation is very difficult, yes, especially when to comes to drugs since most experimental study designs would be immoral to actually use (i.e. it’s immoral to give someone a drug that has a high potential for causing harm, in this case addiction and possibly mental illness). But if you try to control for more and more extraneous factors you could get a clearer picture of the causal relationship. So basically study design is of paramount importance here, and more correlational studies of the same design will not help much. There are many studies out there that show a correlational relationship between smoking weed and developing sz, but there are also studies that are different or have controlled for more factors that indicate this relationship is not causal.

IMHO the truth is probably somewhere in-between, e.g. that smoking weed does change your brain, but this change does not cause schizophrenia, although it may lead to an earlier age of onset for those who were already on their way to getting sz.


my opinion to.


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To be honest I think if you have psychotic illness you should probably avoid most street drugs. But if a day comes when recreational drugs are standardised and formalised, and the effects of them are thoroughly investigated, I would like to try some again (under doctor supervision).

How do you cope with all the weed smoking. It is difficult for me to deal with the mental illness and the weed use. I continue to tell my son, the weed is blocking his progress with psych meds.

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for me it was a perfect storm of heavy drug use (lots of pot) and an incredible amount of stress and pressure which caused me to have my break at 24.
Ive tried to smoke pot since and it causes instant paranoia and psychosis.

I don’t deal with it. I mean, at first I was concerned, when he came home from the hospital and expressed an interest in smoking. He lives with his dad and sister. I live with my fiance and we are only about 20 minutes away so I see my son often. So I really have no control over the situation. He is on an antipsychotic which he gets once a month by injection and he’s been fine, other than having no life to speak of. He has most of the negative symptoms and I am so sad to see him missing out on life, but that’s the illness. :frowning: I don’t think the weed has made him worse. But I don’t know . . .he’s 28 years old and I just have to learn I can’t control everything. The weed is basically his only joy now. I don’t see an end to it.

Thanks for your reply. My son has been battling with this disorder since 2013. He is currently on Invega Sustenna (234), which we just increased. Last year he was on 156 mg injections and doing well, he slowed down on the weed use and returned to work. But he decided to discontinue his meds and it took 3 months for his symptoms to return. Now that he is back on the monthly injection he is not as stable as before and the weed use has tripled. It’s a hard journey.

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I’m sorry :frowning: My biggest fear is that he might try to quit the medication, he is also on invega sustenna shot) His commitment was in January 2013, for one month. So far he’s been very good about complying, not because he knows . . .in fact, I suspect he doesn’t really believe he has schizophrenia, but takes the medication believing he has to because of the court order. It is a very hard journey, yes. The other day, I tried probing him as carefully and as gently as I could to get him to talk to me, tell me about himself, about how he feels, etc. He didn’t want to talk about it. :confused: