Marijuana and Schizophrenia

[PainRack]

schizio cause

Use of street drugs (including LSD,methamphetamine,marijuana/hash/cannabis) have been linked with significantly increased probability of developing schizophrenia. This link has been documented in over 30 different scientific studies (studies done mostly in the UK, Australia and Sweden) over the past 20 years. In one example, a study interviewed 50,000 members of the Swedish Army about their drug consumption and followed up with them later in life. Those who were heavy consumers of cannabis at age 18 were over 600% more likely to be diagnosed with schizophrenia over the next 15 years than those did not take it. (see diagram below). Experts estimate that between 8% and 13% of all schizophrenia cases are linked to marijuna / cannabis use during teen years.

Many of these research studies indicate that the risk is higher when the drugs are used by people under the age of 21, a time when the human brain is developing rapidly and is particularly vulnerable.

People with any biological predisposition towards schizophrenia are at the highest risk -- unfortunately its impossible to accurately identify this predisposition beforehand ( a family history of mental illness is just one indicator of such a predisposition). [see causes and prevention of schizophrenia for more information on all risk factors linked to a person developing schizophrenia]

Researchers in New Zealand found that those who used cannabis by the age of 15 were more than three times (300%) more likely to develop illnesses such as schizophrenia. Other research has backed this up, showing that cannabis use increases the risk of psychosis by up to 700% for heavy users, and that the risk increases in proportion to the amount of cannabis used (smoked or consumed). Additionally, the younger a person smokes/uses cannabis, the higher the risk for schizophrenia, and the worse the schizophrenia is when the person does develop it. Research by psychiatrists in inner-city areas speak of cannabis being a factor in up to 80 percent of schizophrenia cases.

Professor Robin Murray (London Institute of Psychiatry) has recently (2005) completed a 15-year study of more than 750 adolescents in conjunction with colleagues at King's College London and the University of Otago in New Zealand.

Overall people were 4.5 times more likely to be schizophrenic at 26 if they were regular cannabis smokers at 15, compared to 1.65 times for those who did not report regular use until age 18.

Many researchers now believe that using the drug while the brain is still developing boosts levels of the chemical dopamine in the brain, which can directly lead to schizophrenia.

Professor John Henry, clinical toxicologist at Imperial College London said research has shown that people with a certain genetic makeup who use the drug face a ten times (1000%) higher risk of schizophrenia. (for example - if your risk of schizophrenia was 6% (due to a family history of mental illness) prior to taking cannabis, it could be 60% -- or more likely than not - after taking cannabis). Every person is different (i.e. has different genes and different environments) - so this "10 Times Higher Risk with cannabis use"- is just a generalization, and it may or may not apply to a given person.

The increased risk applies to people who inherit variants of a gene named COMT and who smoked cannabis as teenagers. About a quarter of the population have this genetic make-up and up to 15 per cent of the group are likely to develop psychotic conditions if exposed to the drug early in life. Neither the drug nor the gene raises the risk of psychosis by itself.

A recent Dutch study showed that teenagers who indulge in cannabis as few as five times in their life significantly increase their risk of psychotic symptoms.

The increase in evidence during the past decade could be tied to the increased potency of marijuana. A review by the British Lung Association says that the cannabis available on the streets today is 15 times more powerful than the joints being smoked three decades ago.

Schizophrenia can sometimes be triggered by heavy use of hallucinogenic drugs, especially LSD; but it appears that one has to have a genetic predisposition towards developing schizophrenia for this to occur. There is also some evidence suggesting that people suffering from schizophrenia but responding to treatment can have an episode as a result of use of LSD. Methamphetamine and PCP also mimic the symptoms of schizophrenia, and can trigger ongoing symptoms of schizophrenia in those who are vulnerable.

Melbourne University's Professor David Castle stated in a February, 2005 interview that heavy drug use during formative times of life, such as the years at school, could affect the way a teenager or young adult thought, impairing cognitive ability and having a long-term impact on job prospects. Victorian studies had revealed that regular use of cannabis by adolescent girls could trigger long-term depression. And for those vulnerable to a psychotic disorder, even a small amount of cannabis could pose a threat.

Professor Castle, author of the book Marijuana and Madness, has said that those people with this "psychotic proneness" were those who had a family history of mental illness or who had had a bad response on their first use of cannabis or to a tiny amount. Others at risk included those who had experienced a psychotic episode where they had paranoid thinking or heard a voice calling their name. Professor Castle said experiencing such a one-off episode was far more common than people thought.

"People with such a vulnerability should avoid cannabis like the plague," he said.

Without the effects of the drug, such a person might live their whole life without ever experiencing mental health problems. It has been estimated, for example, that between 8% and 13% of people that have schizophrenia today would never have developed the illness without exposure to cannabis.

Professor Castle compared the effect to feeding sweets to a diabetic. While high sugar content foods did not cause too many problems for most people in the short term, they could be catastrophic for diabetics.

He said there was an accumulative effect when it came to cannabis use and schizophrenia. Those who used the drug more than once a week were more prone to needing hospitalisation and often suffered other associated problems such as the breakdown of relations with their family, isolation, crime and violence.

* Cannabis impacts on neurotransmitters that regulate how arousal and stress are managed in the brain. Cannabis takes a long time to metabolise, and can quickly build up to high levels in the body. Once you get to this point, there is a real risk of depression or schizophrenia being triggered.

* A Swedish study of 50,000 military conscripts found heavy use of cannabis increased the risk of suicide by four times (400%). A Victorian study of 2332 adolescents found weekly use increased the risk of suicide attempts among females by five times. Weekly use as a teenager doubled the risk of depression and anxiety. Daily use at the age of 20 boosted the risk of depression and anxiety by five times (500%).

Thoughts? Rebuttals?

[General Zod]

I find it curious that there's no mention of what they consider to be "regular use". I've also never heard of someone having psychotic episodes from their first exposure to marijuana. Typically it involves having the munchies and totally spacing out. . .

[Grandtheftcow]

I find it curious that there's no mention of what they consider to be "regular use". I've also never heard of someone having psychotic episodes from their first exposure to marijuana. Typically it involves having the munchies and totally spacing out. . .

The article states that continued exposure to the drug increases the risk of developing such mental disorders.

This isn't anything like the 50s reefer madness silliness.

[General Zod]

I find it curious that there's no mention of what they consider to be "regular use". I've also never heard of someone having psychotic episodes from their first exposure to marijuana. Typically it involves having the munchies and totally spacing out. . .

The article states that continued exposure to the drug increases the risk of developing such mental disorders.

This isn't anything like the 50s reefer madness silliness.

Once again, there is no defined "regular use" or "continued exposure" for that matter. What are they talking about here? One or two joints per day? 5 or 6 joints per day? How much exposure? 5 or 6 per day for a month or more straight? Numbers do help here you know.

[Grandtheftcow]

Once again, there is no defined "regular use" or "continued exposure" for that matter. What are they talking about here? One or two joints per day? 5 or 6 joints per day? How much exposure? 5 or 6 per day for a month or more straight? Numbers do help here you know.

The best I can find from the article is.

and that the risk increases in proportion to the amount of cannabis used (smoked or consumed).

The more you use it the more likely you are to develop such symptoms.

Do we really need a hard number for this?

[Elheru Aran]

Once again, there is no defined "regular use" or "continued exposure" for that matter. What are they talking about here? One or two joints per day? 5 or 6 joints per day? How much exposure? 5 or 6 per day for a month or more straight? Numbers do help here you know.

The best I can find from the article is.

and that the risk increases in proportion to the amount of cannabis used (smoked or consumed).

The more you use it the more likely you are to develop such symptoms.

Do we really need a hard number for this?

Actually yes. Ordinary use is probably about a joint every few weeks or so. That's a pretty small amount. If it turns out that they got these numbers from someone who was smoking weed at a rate of like six joints a day, though...

[RedImperator]

So kids shouldn't take drugs and you shouldn't smoke marijuana in excess. This is new....how?

[General Zod]

Once again, there is no defined "regular use" or "continued exposure" for that matter. What are they talking about here? One or two joints per day? 5 or 6 joints per day? How much exposure? 5 or 6 per day for a month or more straight? Numbers do help here you know.

The best I can find from the article is.

and that the risk increases in proportion to the amount of cannabis used (smoked or consumed).

The more you use it the more likely you are to develop such symptoms.

Do we really need a hard number for this?

If an otc drug says taking too much can be dangerous to your health, I damn well expect to have a solid amount listed instead of "too frequently" before putting it into my system without knowing how much is dangerous. So yes, we really do need a hard number for this.

[kheegster]

Kind of OT, but Prof. John Henry of Imperial College mentioned above was the guy interviewed by Ali G on drugs. He also helped diagnose dioxin as the cause of Ukrainian President Yushchenko's poisoning.

[Darth Wong]

Once again, there is no defined "regular use" or "continued exposure" for that matter. What are they talking about here? One or two joints per day? 5 or 6 joints per day? How much exposure? 5 or 6 per day for a month or more straight? Numbers do help here you know.

The best I can find from the article is.

and that the risk increases in proportion to the amount of cannabis used (smoked or consumed).

The more you use it the more likely you are to develop such symptoms.

Do we really need a hard number for this?

If an otc drug says taking too much can be dangerous to your health, I damn well expect to have a solid amount listed instead of "too frequently" before putting it into my system without knowing how much is dangerous. So yes, we really do need a hard number for this.

No, you need to provide something better than anecdotal evidence to refute this study. What the fuck do you think this is, the Charlie Brown Dipshit Kiddie Debate Class? Do you honestly think you can knock down medical studies with idiotic bullshit like "I've never personally heard of" etc?

[Imperial Overlord]

It's not new knews that there are enviromental triggers for schizophrenia, living depressed urban area also ups the odds. Studying drug use with schizophrenics and casuality can be a tricky affair as a number of schizophrenics take drugs to self medicate and try to manage with their schizophrenia symptons, but that's clearly not what is happening in this study.

[Darth Wong]

I thought it was interesting to see that a few experimentations seemed to have no correlation whatsoever with the likelihood of schizophrenia, but there was a huge increase for people who had used it 50 times or more by the time they turned 18. Even 10 times made a big difference.

[Grandtheftcow]

I thought it was interesting to see that a few experimentations seemed to have no correlation whatsoever with the likelihood of schizophrenia, but there was a huge increase for people who had used it 50 times or more by the time they turned 18. Even 10 times made a big difference.

Hey someone clicked the link!

If I'm reading the bar graph right its not just how often someones used the drug but how many times they've used it. That's a big slap in the face to those who claim pot is completely harmless and has no long lasting effects.

[Einhander Sn0m4n]

I thought it was interesting to see that a few experimentations seemed to have no correlation whatsoever with the likelihood of schizophrenia, but there was a huge increase for people who had used it 50 times or more by the time they turned 18. Even 10 times made a big difference.

Hey someone clicked the link!

If I'm reading the bar graph right its not just how often someones used the drug but how many times they've used it. That's a big slap in the face to those who claim pot is completely harmless and has no long lasting effects.

If my interpretation is right, it's the number of schizophrena cases per thousand versus the number of marijuana sessions reported to have partaken in by age 18.

My analysis is that marijuana has a negative impact on teenage users, particularly heavy users, but with a marked ramp-up through even moderates.

My hypothesis is marijuana use interferes with development of the teenage brain. This likely has no bearing upon adult-onset marijuana use however heavy or light.

My recommendation is to commission a study of marijuana smokers who've started only after age 18 and attempt to find any trend of schizophrenia risk across the usage spectrum.

[Einhander Sn0m4n]

EDIT: My recommendation to lawmakers is, if marijuana use has little effect on schizophrenia incidence across the usage spectrum for adults over 18, to strongly regulate marijuana as per alcohol or tobacco.

[Superman]

Working in a medical rehab, I can tell you that the rate of addicted and alcoholic people with co occurring mental disorders is very high. There have been studies, for example, that show something like 80% of heroine addicts are also bipolar. The effects of the drugs may also different; heroine addicts tend to become hyped up on it instead of slowing down like everyone else. We see a similar effect with speed addicts who are also ADD; they calm down and focus. And from what I have seen, alcoholics definitely go through periods of manic energy, and then slow down later.

I guess my point is that people who use substances frequently often do so because they are self-medicating; that is, they are unknowingly "treating" their mental illness (they're just doing it dangerously with unsafe drugs), which makes them feel better. The question to me is which came first, the predisposition for the mental disorder or the addiction?

[Surlethe]

The question to me is which came first, the predisposition for the mental disorder or the addiction?

I had precisely the same thought, but the article seems to point toward addiction coming first. It notes that the drugs don't only increase risk (i.e., there's a correlation), but also propensity to become psychotic. At least, that's how I read it.

[Darth Wong]

The two may be inter-related somehow, so there isn't a clean-cut cause and effect relationship. But I don't see why people would be so knee-jerk skeptical; have they forgotten that narcotic drugs alter your brain chemistry, which is how they work?

If someone said that pharmaceutical anti-depressant drugs can fuck up your personality or your mind over time, no one would bat an eyelash at it. Of course they do, they mess with your brain, right? But for some reason, you say the same thing about narcotics and people are shaking their heads saying "No, I don't see how that can happen, there must be some other explanation ..."

[Trytostaydead]

Well, the treatment of schizophrenia itself is based off of the "dopamine hypothesis" which is the theory that there is an EXCESS of dopamine in the mesolimbic system. A lot of recreational drugs work on the dopamine pathway, and THC has been shown to increase the secretion of dopamine.

Though as stated earlier, there may be a genetic predisposition as well and the use of drugs just speeds it up, pushes it across the edge, etc. A quick perusal of pubmed articles, it seems more researchers are hesitant to say which came first, the chicken or the egg, but are content to continually proclaim the comorbidity of substance abuse and various psychoses.

[Superman]

The two may be inter-related somehow, so there isn't a clean-cut cause and effect relationship. But I don't see why people would be so knee-jerk skeptical; have they forgotten that narcotic drugs alter your brain chemistry, which is how they work?

If someone said that pharmaceutical anti-depressant drugs can fuck up your personality or your mind over time, no one would bat an eyelash at it. Of course they do, they mess with your brain, right? But for some reason, you say the same thing about narcotics and people are shaking their heads saying "No, I don't see how that can happen, there must be some other explanation ..."

In my admittedly biased opinion, I tend to agree with the dimensional model of addiction and alcoholism; meaning that addiction is a symptom of underlying mental disorders. In alcoholics for example, I can't tell you how many times I've heard people say they started drinking because they suddenly found mental peace. They found, for once, a way to calm their mind and get relief from intrusive thoughts that they could never "shut off." To many clinicians, this is a good description of a manic state associated with bipolarity or what's called dysthimia. The alcohol brings them down and they can relax; it depresses the central nervous system as a benzodiazepine medication also would. Add a genetic predisposition this and you may get an addict.

Similarly, I've heard many people addicted to methamphetamine and cocaine say that when they use, they suddenly find they can "keep up" with everyone else. They can focus and finally organize, at least initially. Again, they get some momentum going and later find they can't stop.

But what you are saying is also true; I can tell a meth head from a mile away, even when they've had years of sobriety. Brain damage is a likely result from almost any substance of abuse. Most people become depressed and end up later needing psychiatric treatment. A good friend of mine who is an addiction medicine physician is convinced that years of marijuana use leads to chronic depression.

[RedImperator]

The two may be inter-related somehow, so there isn't a clean-cut cause and effect relationship. But I don't see why people would be so knee-jerk skeptical; have they forgotten that narcotic drugs alter your brain chemistry, which is how they work?

Decades of bald-faced lying from the government to justify lousy drug control policies seem to be the most likely cause to me. There have been a lot of studies which "prove" this or that claim which have later been discovered to do no such thing, and more claims which have been just plain made up. This one seems legit, both based on the source and because it's been suspected for a long time marijuana has a connection to schizophrenia, but the skepticism is justified based on the amount of wolf-crying that's been going on about cannabis since the 1930s.

[PainRack]

I guess my point is that people who use substances frequently often do so because they are self-medicating; that is, they are unknowingly "treating" their mental illness (they're just doing it dangerously with unsafe drugs), which makes them feel better. The question to me is which came first, the predisposition for the mental disorder or the addiction?

Doesn't the disease model work on the principle that drug addiction occurs because of "self medication" and self help?

[Superman]

I guess my point is that people who use substances frequently often do so because they are self-medicating; that is, they are unknowingly "treating" their mental illness (they're just doing it dangerously with unsafe drugs), which makes them feel better. The question to me is which came first, the predisposition for the mental disorder or the addiction?

Doesn't the disease model work on the principle that drug addiction occurs because of "self medication" and self help?

Not necessarily. "Disease" is a broad term which basically means an abnormality relating to the body. It's funny how some people will get on their soap boxes and preach that addiction is not a disease, yet they don't have a clue as to what the term actually means. Addiction may not be due to the invasion of pathogens (and cancer may not be either, for that matter), but it is currently accepted as a true disease.

[Stark]

Decades of bald-faced lying from the government to justify lousy drug control policies seem to be the most likely cause to me. There have been a lot of studies which "prove" this or that claim which have later been discovered to do no such thing, and more claims which have been just plain made up. This one seems legit, both based on the source and because it's been suspected for a long time marijuana has a connection to schizophrenia, but the skepticism is justified based on the amount of wolf-crying that's been going on about cannabis since the 1930s.

It's still just a knee-jerk response, regardless of the retarded history of hopelessly biased or misinterpreted studies in the past. But hey, drug users don't want to think that their habit of using these substances could be harmful... just like smokers.

[Alerik the Fortunate]

It is interesting that there (from what my limited scanning gathered) is a correlation between the total number of times used and likelihood of schizophrenia. Perhaps this is why coneheads are permitted but two uses of the pleasure spools. I had always wondered about that.