August 30, 2006

Marijuana and Schizophrenia - Public Policy Implications

Two new research journal articles came out in the August,2006 issue of the "Canadian Journal of Psychiatry" on the issue of how cannabis (marijuana) use is linked to increased risk of schizophrenia - and what the public policy should be given what they describe as this now generally-accepted fact in psychiatry today.

In their research study the schizophrenia researchers state:

"Evidence from 6 longitudinal studies in 5 countries shows that regular cannabis use predicts an increased risk of a schizophrenia diagnosis or of reporting symptoms of psychosis. These relations persisted after controlling for confounding variables, such as personal characteristics and other drug use. The relation did not seem to be a result of cannabis use to self-medicate symptoms of psychosis. A contributory causal relation is biologically plausible because psychotic disorders involve disturbances in the dopamine neurotransmitter systems with which the cannabinoid system interacts, as demonstrated by animal studies and one human provocation study.

It is most plausible that cannabis use precipitates schizophrenia in individuals who are vulnerable because of a personal or family history of schizophrenia."

In a newspaper article in the Ottawa Citizen (Canada), the researchers stated:

"Cannabis use can trigger schizophrenia in people already vulnerable to the mental illness -- and this fact should shape marijuana policy".

The link between marijuana use and schizophrenia is generally accepted in the psychiatric community. The problem is that the vulnerable population -- mostly teenagers -- generally isn't eager to absorb the message.

In a related article, the authors discussed the public policy implications of the marijuana/cannabis link to schizophrenia, saying:

The observational evidence and biological plausibility of the hypothesis that cannabis is a contributory cause of psychosis is at least as strong as evidence for causal relations between heavy alcohol and amphetamine use and psychosis. On public health grounds, there is a good case for discouraging cannabis use among adolescents and young adults. It remains uncertain how best to discourage use and at whom campaigns to reduce cannabis use should be targeted.

We should discourage young adults seeking treatment in mental health services from using cannabis and inform them of the probable mental health risks of cannabis use, especially of early and frequent use. We must exercise caution in liberalizing cannabis laws in ways that may increase young individuals’ access to cannabis, decrease their age of first use, or increase their frequency of cannabis use. We should consider the feasibility of reducing the availability of high-potency cannabis products.

The Ottawa Citizen summarized the study as follows:

In a companion article, Hall and Degenhardt argue that young people should be warned of the marijuana-schizophrenia link, since most schizophrenics are diagnosed by their late teens, about the same time teens are experimenting with cannabis.

"There are a lot of other reasons to discourage young people from using cannabis," said Hall, who believes that young people should know about the link and also be on the lookout for schizophrenic symptoms that show up among their friends who smoke marijuana.

Wende Wood, a psychiatric pharmacist at the Toronto-based Centre for Addiction and Mental Health said people who want to smoke marijuana should wait until they are at least 25. The human brain had developed fully by that time, and if schizophrenia is present, it has usually already become apparent. Canada's legal drinking age is too low for the same reason, she added.

Cannabis users who have schizophrenia are more difficult to treat and marijuana makes their psychoses worse, she said. ...

The problem is, no one knows how to gauge predisposition to schizophrenia.

The research paper suggests the following, in terms of clinical implications of the research:

Screening all patients with psychoses and advising those who use cannabis to stop should discourage cannabis use among the clients of mental health services and reduce the number of cannabis-related psychoses.

More In-depth Information: Marijuana / Cannabis and Schizophrenia

Related Reading: UK advocacy group urges Govt. to Educate Public about Mental Health risks of Cannabis / Marijuana

Academic Research Sources:

Is Cannabis Use a Contributory Cause of Psychosis? Louisa Degenhardt, MPsych(Clinical), PhD, Wayne Hall, PhD, August, 2006,Canadian Journal of Psychiatry

What Are the Policy Implications of the Evidence on Cannabis and Psychosis? Wayne Hall, PhD, Louisa Degenhardt, MPsych(Clinical), PhD, August, 2006, Canadian Journal of Psychiatry


I use Marijuana To help with my schizophrenia symptoms and to calm me down relaxing helping my brain shut down at night for a better sleep.....not really sure if Marijuana may have caused any of my cascade in to schizo-affective disorder but the hard fact is it is a key medication in my current RX rejiment

Posted by: Michel Flannery at August 30, 2006 07:21 PM

I smoked grass for approx. 25 yrs. and got a diagnosis. Now, when I smoke it, it's been almost 7 yrs., I just get super paranoid. Therefore, I quit. Chris

Posted by: Chris at August 31, 2006 11:30 AM

I am a former user of marijuana and quit almost 7 years ago because it just made me ulta-paranoid. I used for approx. 25 years.

Posted by: Chris C. at August 31, 2006 11:36 AM

I used cannabis from the age of 15 and stopped due to chronic paranoia a few years later. I was diagnosed aged 19 after being acutely ill. I tampered with it again after recovering, and got paranoia anxiety, followed by depression. I no longer use it.

Posted by: Andrew Locke at September 5, 2006 07:29 AM

I've been using it for 5yrs, however at strickly regulated dosages (with dosage assistance/supervision) with meditation; followed by liquid multivitamin and ginko biloba 30-45 min after (i don't know why but earlier or later and I might as well skip the second part and get ready for a lousy day). I've found it useful for "stilling the mind" and with PTSD associated with other peoples reactions to schizophrenia. I've also hide behind the high around people who were more accepting of pot then insanity. Also, due to a local peculiarity, I've found it more readily available, and cheaper than wrestling with someone elses discrimination and/or god complex. *note - without the love of and trust in my girl, I never would have made it. and when she said to easy up the dose on the latest bag - SHE MEANS IT!!

Posted by: paul vona at September 9, 2006 10:50 PM

My father was working in indian Army twenty year he was continually taken alcohol
And now he is retired and living in village last seven years he is addicted of marijuana and last seven year he is also suffering for schizophrenia and last four year we are giving some medicine for consultant doctor prescribed but he was now suffering very bad condition and with family member is also looking ill with him.
I am only one son and I am working abroad in UAE Abu Dhabi in Hyundai Company
Now I am also very reluctant with his attitude and condition please give any suggestion and please give me any address of Doctor in India please help me I am feeling alone what can I do ……. I feel helpless please help me help me

Email –
Phone No-00971-508375518

Posted by: ADITYA JHA at September 30, 2006 03:56 AM

Hello, i started usin bud in high school freshman year had its ups and downs with he whole being illegal but i feel i can pull off using bud as long as i dont procrastinate things more that i already do.

Posted by: Chris B at October 25, 2006 11:53 AM

I was diagnosed with schizophrenia while attending a highly competitive state university. I became hopelessly paranoid with the central delusion being that an older man(about the age of my parents) known to me both from a college fraternity that hazed and a political action group I worked for was out to get me/kill me. Two things are especially relevant. One, this man was a marijuana user and I wonder if the "contact" high from talking to him hours on end amid chess games could transmit bizarre thinking(some of his stories were impossible to follow). Second, I remember clearly that I smoked some marijuana after I had begun to have purely speculative fear of this man killing me over the political falling out, and that while high on the pot I was with a girl also involved in hazing who expressed a keen interest in my fear of this man("So you won't even go near him"). The strange thing is that the high and it's paranoia somehow crossed over into my normal thinking and intensified the speculative into a "real" plot. Yet of course, this man had made threats towards. I remained psychotic for a couple of years and the plot thickened considerably and became bizarre as well. This psychosis felt a lot like a bad high from marijuana except far, far worse because I could not wait it out. Incidentally, that was the LAST time I ever smoked the stuff.

Posted by: anonymous at October 25, 2006 06:48 PM

I smoked bud for years, heavily over the summer, thought everything was great and all of a sudden became ultra paranoid. I also think I constantly have to satisfy everyone around me and I'm generally waaay more anxious so I quit. No matter what, sooner or later weed will start making you paranoid.

Posted by: anonymous at November 20, 2006 12:05 PM

If you're using cannabis to ease your symptoms you should instead use melatonin 1-3mg before going to bed. Schizophrenia sufferers are typically pre-deficient in melatonin and DHEA (DHEA 5mg in AM) Melatonin and DHEA normally decrease as we age, but for Schizophrenia, they decrease too soon.

Posted by: family at November 29, 2006 07:06 AM

Yeah, I totaly recomend against the useage of Marijuana.
I smoked it for about 3 years straight.
And while before i was sort of a parinoid person by the end of the 3 years i was a full out parinoid-schizophrenia case.

Always takeing things in and worrying and thinking that someones out to get me and stuff, and the thing is its crippeling because while deep inside you know it sounds a bit foolish it seems so real in your head.

Marijuanas bad stuff, I dont care what anyone says.

Posted by: anonymous at December 7, 2006 12:53 AM

Weed definitely makes you paranoid sooner or later , I learned that the hard way.
My life became a mess. Paranoia takes over in every part of your life.
I strongly recommend not to use it.

Posted by: Andre PA at February 22, 2007 11:24 AM

I have a friend who, he says, was falsely labled paranoid schizophrenic, yet in the short time I've known him, it is clear he believes "they" are out to get him (whoever "they" are) and have drugged him and tortured him. When I ask for details or who "they" are, he cannot come up with anything concrete or any evidence. He smokes marijuana every day, several times a day and I don't know for how long. He said he quit for a particular job and then something happened to him and he lost the job. He said he would never "change his lifestyle" again, as if having done that was the reason he lost the job. I don't know if the thing that happened to him was imagined (paranoia) or real, but he thinks it's real. I want to help, but he's likely not going to be too receptive of paranoia/marijuana connections. Even if I am able to get him to see the connection, is there a road to recovery or is the damage done? He's restless and distractable in addition to being suspicious. If he knew I was posting this he'd be in a panic, even though I haven't mentioned his name.

Posted by: Shelley at February 26, 2007 11:32 PM

I used hash and LSD, i had the worst trip on acid and since that time i have suffered with various paranoias. I mostly try to ignore what i dont beleive to be rational thoughts but sometimes i get flashbacks and the paranoia comes right back. If i knew 15yrs ago what i know now i wouldnt have touched any type of drug. I dont do drugs anymore and havent for about 8yrs now. This is the first time i have ever spoken of this and i have difficulty talking about it but im finding it harder not to deal with the anxiety and general depression.
I have addisons disease aswell so i know this makes me deficient in dhea, i wondered if anyone knew of anything that could help me out of this crippling nightmare. Please mail me if you can help.

Posted by: john at April 10, 2007 04:06 PM

I smoked cannabis of various strengths and strains for roughly 5 years (through college). I found that during times when external pressures were realistic and under control, my highs were pleasant, free from paranoia and stress, and were generally an excellent and energizing (yet relaxing - a strange but wonderful combination) gateway to enthusiasm for creativity which was gewnerally dampened by my cynical (though cober) outlook. When pressures were beyond my control, cannabis seemed to clarify the situation but did not alleviate the mental stress, and I fell into panic attacks. However, after having not used for many months, I discovered that these panic attacks did not appear related to cannabis use directly. I cannot objectively say if these attacks would have been absent if I had not smoked, but I did notice that in many ways, cannabis use was one of the more benign components of my existence. To think about my growing debt was far more damaging to my well-being, and cannabis seemed to make that introspection brutally honest. I have not smoked in many months, due to occupational obligations, but I do believe that cannabis will play a role in my life much like any other complex herbal substance like garlic or basil. Properly consumed, properly appreciated, and properly measured. And I say this after having realized that according to the latest DSM, I'm not a terribly sound personality.

Posted by: Dan at July 27, 2007 02:52 AM

In the past, I was never the sort of person to believe that pot smoking was any more harmful than drinking a few beers. However, it has been my experience, both personal and observational, that pot definitely brings on paranoia and worsens schizophrenia.
My personal experience has been varied but mainly negative. Usually i get extremely nauseus and paranoid and I can not control it at all. So I dont touch the stuff. But I know that my experience cant be everyones experience and obviously there are benefits to using it so I never judged others for using.
However, looking back at the history of all my relationships with people, both romantic involvements and friendships, I have observed that while sober, my relationship with these people were fine. Happy, pleasant, theres good communication, disagreements are infrequent and are handled calmly. But while they were using regularly (regularly being every day or several times a week) they were distant, lacked interest in relating on a personal level caring only to "space out" in front of the tv or video games. Those are the mild setbacks... the more severe are increased paranoia and argumentativeness when trying to relate to them. I've experienced sudden violent outbursts and anger at completely innocent and unprovoking conversation because they imagined what I was saying was "grilling" them or having an alterior motive or undisclosed agenda. One guy actually told me he could hear what myself and another friend was thinking and swore we we trying to manipulate him or plan something behind his back. Later he accused me of being a witch and having put a spell on him to make him fall in love with me...all because we were on my roof deck at night and the full moon was out. I was wearing a velvet cape at the time because it was freezing out and it was the closest thing to the door I could grab. He was the most extreme, or at least the most obvious. Generally tho, the paranoia is far more subtle but just as damaging to the relationship. Whats worse is that even upon swearing I was not thinking what he thought I was thinking and even proving to him by example that he was indeed way off the mark...he insists on holding onto the paranoid rage and comes up with ridiculous justifications for his actions and blame shifting. The most prevalent I can recall is being told I "should know him well enough by now to know what will piss him off" and I should be "mindful" of that when approaching him with conversation. which would mean I would need to be paranoid that he will be paranoid and react in anger. He gets extremely agitated yelling that its so obvious, how could I not see that he would be angry at whatever it was said or done. Even a simple "hello, whatcha doin?" or "who ya talkin to" has been met with severe suspicion and anger and responded with horrible glaring looks and comments like "dont start with me. dont think i dont know what youre thinking, coming down here checking up on me!" like..WHOA, dude I was just sayin hii and making small talk, fukin chill out man... When not smoking he is polite, responsive, positive, caring and affectionate. When high he argumentative, aggressive, explosive, vindictive, cold, distant, anti-social, ...even seeing me hurt or crying, he feels no remorse and looks at my crying as merely a manipulation tactic. He says things in conversations, either making plans, promises or simply stating what happened or how he feels about a situation and the next time it comes up, be it a month or even 20 minutes later, the story is the exact opposite or he denies even saying it at all. As far as I know he has never been diagnosed with a mental illness but I have very limited contact with his friends and family. he keeps me away from them almost entirely. But just because a person wasnt diagnosed as having it doesnt mean they dont have it...many people, like him, refuse to see Drs...probably because they know, or think they know, theyll be told something they wont want to hear. I do not think I could ever convince him that his pot smoking effects him so severely. He denies that pot is even a drug. Hes in deep denial. No matter how much proof I offer him. I am afraid that this will only get worse for him if he does not stop smoking or gets psychiatric help.

I hope more conclusive research is done on this soon. The evidence so far completely backs up my personal experiences with the drug and with people using it regularly.

Yanno donuts are good too...but ya cant eat them every freakin day and expect to stay healthy. Same goes for marijuana.

if anybody has any further information or websites to help me approach the situation or more articles with unbiased, well documented, factual evidence I can pass on to these people i would greatly appreciate it.

thank you.

Posted by: Yurii at September 6, 2007 05:53 AM

I used to smoke marijuana regularly, one day i was smoking when my touch with reality suddenly completely changed, and ever since that day, i feel completely different, sometimes ill be lying in bed and ill disconnect from my body and it feels very weird. i was looking for a way to find out what was wrong with me for a while, online and other places, and i finally found something that sort of explained what my experience felt like, if anyone has had this experience you will understand exactly how this is described or if anyone knows about it, please let me know, will my life ever come back to me??(also i might add, i tried smoking sometime after the day it all happened and i could not walk because i felt as if i was stuck)....."As the marijuana user becomes moderately intoxicated, the space/time matrix of experience seems to change; distances he moves around in change in size, time slows down, and sound begins to have some structuring effect on the space/time matrix. [...] He may sometimes become so lost in inner thoughts and fantasies that it takes some time to reorient to where he is. At the highest levels, time may seem to stop, actions to be out of the framework of physicalistic time, and he may also completely lose touch with the ordinary space/time continuum and experience floating in limitless space."

Posted by: van halen at November 29, 2007 06:24 PM

I would like to retract my statement I posted back in 2006 because I feel it is very inaccurate ...and I no longer support that view...

Posted by: Michel at April 8, 2008 06:21 PM

Post a comment

Please enter this code to enable your comment -
Remember Me?
(you may use HTML tags for style)
* indicates required