Marijuana Smoking Linked to Mental Illness

A new meta-analysis of research involving 20,000 patients has shown that people who smoke marijuana could develop psychosis (an abnormal condition of the mind characterized as a loss of contact with reality and sometimes including hallucinations, delusions and disordered thoughts) 2.7 years earlier than those who don’t smoke marijuana.

The research was a review of 83 previous studies on the relationship between substance abuse and psychotic illness. “Heavy cannabis use starting at a young age carries a very much greater risk than modest use as an adult,” said study author Dr. Matthew Large. (Source: Businessweek.com) Youth need to be made aware of the risk associated with smoking marijuana, along with other risk factors for psychotic disorders, a general category which includes schizophrenia.

The study also looked at alcohol use and the onset of psychosis, but did not observe it accelerated the condition’s starting point.

Cheryl M. Corcoran, MD, a researcher from Columbia University commented on the research, saying “This is a very comprehensive study; the authors paid very close attention to methodological issues and considered several important factors in a very sophisticated manner, such as the proportion of males in the different studies.” (Source: Medscape.com) She also said the study does not prove smoking marijuana alone causes psychosis.

It might be that youth suffering from the symptoms of psychosis are drawn to a substance that seems to alleviate some of their pain, without having to face the stigma of mental illness and the involvement of parents or the medical establishment. Another factor could be they find some acceptance in a sub-culture with its own self-medicating practices, music, style of dress and jargon, because psychosis can result in extreme social isolation.

Previous research has indicated there could be a link between the onset of schizophrenia and regular marijuana smoking: “Researchers in New Zealand found that those who used cannabis by the age of 15 were more than three times (300 percent) more likely to develop illnesses such as schizophrenia.” (Source: Schizophrenia.com)

The recent tragedy in Arizona involved a young adult shooter who has been speculated to suffer from schizophrenia, and was reportedly a regular marijuana user. Most people suffering from mental illness don’t ever resort to such actions, but if undiagnosed and untreated it can progress to a point of violent behavior.

Image Credit: Bogdan

Disclaimer: The views expressed above are solely those of the author and may not reflect those of
Care2, Inc., its employees or advertisers.

Diane L.

1:10AM PDT on May 11, 2012

Well said, Kimberlee. I guess Heidi doesn't realize that she wouldn't have lived long enough to be able to be on the internet without the "aid" of taking some drugs in her own life. Everything ingested is a drug of some kind. Aspirin is a "drug". Penicillin is a drug, and wanna' bet if anyone has lived past the age of 5 years of age without having taken aspirin or been given any penicillin at some time or another? Native Americans smoked peote and other naturally growing substances as both healing and for enjoyment. Want to guess what was in those 'peace pipes"? Peote comes from a cactus. Heroin comes from poppies. Cactus and poppies are plants. We can make tea from dandelions and clover. I guess anyone who drinks clover tea is taking drugs.

send a green star

Kimberlee W.

12:06PM PDT on May 10, 2012

Heidi - One person's poison is another person's cure.

Just because something is a drug does not in any way necessitate that it's "bad".

Heidi A.

12:47AM PDT on May 9, 2012

I have no idea why anyone would CHOOSE to poison their bodies with any drug.

12:35AM PDT on May 9, 2012

Adrienne, welcome to the world of Care.2 articles! Some staff writers are obviously less inclined to write both sides of a topic than others, and Jake is one who I have had a few issues regarding that in the past. I do think he tries a bit harder than some to be factual. Sometimes, a writer will take some tabloid "blog" story and run with it and it can be extremely silly and unfactual. Sometimes, the writer just is very opinionated, personally, so does NOTHING to point out the other views. It's up to us to not go off the deep end when reading these things and overreact, which many members do, especially with child or animal abuse/cruelty stories. The nutritional ones get a bit heated also.

Adrienne A.

4:15PM PDT on May 8, 2012

Okay, this is what I most dislike about this type of "informative" article. Here is the rest of the quote, left out by Jake.
The meta-analysis found that people who smoked marijuana developed psychotic disorders an average 2.7 years earlier than people who did not use cannabis. But the review also found that people who used any illegal drug suffered psychosis two years earlier than non-users, not a large difference.

While alcohol use was not associated with early onset, the studies reviewed could not rule out the influence of cigarette smoking, which is a common habit of people with psychotic disorders and those who smoke marijuana. In many of the countries from which the data was gathered, in fact, cannabis is typically smoked mixed with tobacco. The researchers argue that cigarette smoking—unlike marijuana— does not worsen hallucinations or paranoia in patients with schizophrenia, so they believe that tobacco does not account for earlier onset.

It is very biased to only show part of the story, just as the current article laying the blame for depression and other psychiatric problems on gluten leaves out the part that shows the study was on young people already suffering from celiac disease, not basically healthy models. Therefore, the article was really an anti-gluten pitch more than factual, and this anti-cannabis story clearly biased in its lack of complete and trackable information.

4:14PM PDT on May 8, 2012

Okay, this is what I most dislike about this type of "informative" article. Here is the rest of the quote, left out by Jake.
The meta-analysis found that people who smoked marijuana developed psychotic disorders an average 2.7 years earlier than people who did not use cannabis. But the review also found that people who used any illegal drug suffered psychosis two years earlier than non-users, not a large difference.

While alcohol use was not associated with early onset, the studies reviewed could not rule out the influence of cigarette smoking, which is a common habit of people with psychotic disorders and those who smoke marijuana. In many of the countries from which the data was gathered, in fact, cannabis is typically smoked mixed with tobacco. The researchers argue that cigarette smoking—unlike marijuana— does not worsen hallucinations or paranoia in patients with schizophrenia, so they believe that tobacco does not account for earlier onset.

It is very biased to only show part of the story, just as the current article laying the blame for depression and other psychiatric problems on gluten. The quote leaves out the part that shows the study was on young people already suffering from celiac disease, not basically healthy models. Therefore, the article was really an anti-gluten pitch more than factual, and this anti-cannabis story clearly biased in its lack of complete and trackable information.

11:29PM PDT on Apr 18, 2012

Jane, you are partially correct, but psychosis may be exacerbated by childhood abuse, it isn't necessarily caused by it. If the child is mentally stable (genetically) then he/she can often overcome the abuse and grow into a very normal, healthy adult. On the other hand, the best childhoods cannot change a child born with a predisposition to mental illness or as you've mentioned, schitzophrenia, bi-polar or manic depression.

John M.

7:03PM PDT on Apr 18, 2012

Thats brilliant Jane b, I agree with you 100%, And just as in the same way alcohol brings a lunatic out in people as well, the lunatics in there alright, all the things that alcohol causes us(not all of us and not always) to feel and act like, when over intoxicated are in us, alcohol gives them life in the same way marijuana can give life to underlying unresolved, concerning feelings and thoughts, some people can some people cant, and some people just shouldn't, one drug buries everything, the other puts all that under a microscope. you don't have to be einstein to understand what that might do to some either.

Jane B.

5:38PM PDT on Apr 18, 2012

Schizophrenia is a genetic disorder, people are born with it. Marijuana cannot POSSIBLY cause that. And schizophrenics typically snap and get violent, it's part of their illness. What CAUSES psychosis is childhood abuse and sending children to WAR to KILL other HUMANS.
And PEOPLE are the CAUSE of THAT, not marijuana.

Victor M.

10:30AM PDT on Mar 19, 2012

There are medicinal uses for marijuana too