CAMH study shows mental illness associated with heavy cannabis use

People with mental illnesses are more than seven times more likely to use cannabis weekly compared to people without a mental illness, according to researchers from the Centre for Addiction and Mental Health (CAMH) who studied U.S. data.

Cannabis is the most widely used illicit substance globally, with an estimated 203 million people reporting use. Although research has found links between cannabis use and mental illness, exact numbers and prevalence of problem cannabis use had not been investigated.

"We know that people with mental illness consume more cannabis, perhaps partially as a way to self- medicate , but this data showed us the degree of the correlation between cannabis use, misuse, and mental illness," said Dr. Shaul Lev-ran, Adjunct Scientist at CAMH and Head of Addiction Medicine at the Sheba Medical Center, Israel.

"Based on the number individuals reporting weekly use, we see that people with mental illness use cannabis at high rates. This can be of concern because it could worsen the symptoms of their mental illness," said Lev-ran, who conducted the research as a post-doctoral fellow with the Social Aetiology of Mental Illness (SAMI) Training Program at CAMH.

Researchers also found that individuals with mental illness were 10 times more likely to have a cannabis use disorder.

In this new study, published in the journal Comprehensive Psychiatry, CAMH researchers analyzed data from face-to-face interviews with over 43,000 respondents over the age of 18 from the National Epidemiologic Survey on Alcohol and Related Conditions. Using structured questionnaires, the researchers assessed cannabis use as well as various mental illnesses including depression, anxiety, drug and alcohol use disorders and , based on criteria from the (DSM-IV).

Among those will mental illness reporting at least weekly cannabis use, rates of use were particularly elevated for those with bipolar disorder, personality disorders and other substance use disorders.

In total, 4.4 per cent of individuals with a mental illness in the past 12 months reported using cannabis weekly, compared to 0.6 per cent among individuals without any mental illness. Cannabis use disorders occurred among 4 per cent of those with mental illness versus 0.4 per cent among those without.

Researchers also noted that, although cannabis use is generally higher among younger people, the association between mental illness and cannabis use was pervasive across most age groups.

They emphasize the importance of screening for frequent and problem cannabis use among those with , so that targeted prevention and intervention may be employed.

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Citation: CAMH study shows mental illness associated with heavy cannabis use (2013, April 2) retrieved 21 August 2019 from
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Apr 04, 2013
ask any doctor if it is better for you to eat a cup of sugar or eat a cup of MJ and see what he says.

Apr 04, 2013
What exactly is a "cannabis use disorder". Oh, I know, they act high.
Geesh. Of course they are self medicating. Most pharmaceuticals are completely ineffective with many mental illnesses. They also come with horrible side effects for the users.
Cannabis however, depending on the strain will mellow you or help you to concentrate better. It can also cause hallucinations etc. A very good reason for legalizing it for medical use so individuals have access to the proper strains for the needs they have.

Apr 07, 2013
A very good reason for banning it is that if it was legal the rate of accidental deaths through auto accidents or overdose of other drugs would go up dramatically.

the increases costs in the form of accidental death and injury will outweigh any perceived medical benefits, because even ONE accidental death or injury due to substance abuse is unacceptable.

We already have many many thousands of deaths caused by auto accidents involving alcohol each year. We don't need more deaths caused by newly legalized drugs.

Users in Washington lit up publicly, still contrary to the law, in response to the bill allowing private use. Meaning they broke the law anyway, proving they do not care what is legal, safe, or fair, or even if others get killed or injured by their actions. They do it anyway.

It is not acceptable.

Legalized Alcohol and drug use makes me ashamed to be an American, because it violates the human rights of the innocents killed by users.

Apr 07, 2013
Lurker, I'm 100% against marijuana use. I think you are an idiot to use it and that the so called medical marijuana is a joke and only an excuse to legalize it. That said, I believe anything you can grow, should be legal.

As for driving under the influence of any drug or alcohol I believe if you are caught it should be punished as attempted murder. If you kill someone under the influence, you should receive the same punishment as 1'st degree murder.

Apr 11, 2013
IFIFIF The problem with all the ifs is that studies actually have usually shown people under the influence of cannabis driving are safer than those with alcohol. That said, no one who is high on anything that is driving in a manner that is unsafe should do so.
However, police pulling people over arbitrarily is unacceptable as well so unless the person actually was unsafe doing a routine check because the officer "suspects" they might be under the influence is wrong.
You get pulled over for a broken tail lamp you get a ticket for that and unless you have an expired license or some other issue a suspicion because someone has red eyes etc. should NOT give them authority to force a test.
BTW I do not smoke but do advocate for it as I have fibromyalgia and having tried it one time for that several years ago can attest to the fact of it's effectiveness. I did smoke in my late teens and twenties but now would only want it for medicine. Not all of us want to get high. We just want relief.

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