July 14, 2004

Stronger Evidence for Pot-Psychosis Link

After being downgraded to a Grade C drug last year in the UK (as classified under the British Misuse of Drugs Act 1971), cannabis is once again implicated as a primary trigger for schizophrenia-like symptoms, paranoia, and memory problems. Psychiatrist Robin Murray stated that up to 80% of the new admits to mental health wards have a history of smoking pot.

A new study from Yale University school of medicine showed that psychotic symptoms (paranoia, hallucinations, disrodered thoughts, concentration problems, memory loss) were induced in healthy volunteers by injecting them with the active ingredient of cannabis (delta-9-tetrahydrocannabinol). None of the volunteers had a previous history of marijuana use. The results were published in the journal Neuropsychopharmacology ("The Psychotomimetic Effects of Intravenous Delta-9-Tetrahydrocannabinol in Healthy Individuals: Implications for Psychosis." 2004, June 2)

Other research has previously shown strong correlations between cannabis use and the development of psychotic symptoms, particularly in people who smoked frequentaly (two or more joints a week) or had a family history of psychiatric illness. Besides its role in inducing mental illness, cannabis also increases risk for cancer and lung disease.

For the full article, see Harbor Behavioral Healthcare (http://www.harbor.org).

Article: "Cannabis 'is a Trigger for Mental Problems' "(July 12, 2004).

For previous articles and research linking cannabis to schizophrenia symptoms, see 'Street Drugs Increase the Risk of Schizophrenia' in the Causes and Prevention section of schizophrenia.com


I am trying to help my friend. He has been off his meds for about four months. I just don't know what to do for him. thank you,

Posted by: pauline at July 22, 2004 03:13 AM

Are the chances for complete recovery better if the schizophrenia has definitely been caused by drug abuse.

Posted by: monica at August 1, 2004 10:03 AM

Thanks Julia for the information. I strongly suspect my daughter's drug abuse was a trigger for her sz.


Posted by: Moeder at August 4, 2004 06:35 PM

Thats for helping me with my homework!

Posted by: bishoy at August 11, 2005 02:41 AM

I know the risks of smoking pot, however, many of my friends do not and I don't know if they would believe it if it smacked them in the face. I only wish that they would listen, but the pot has really got a hold on them I hope you keep posting all of the new information because I now have schizophrenia but of course for some reason they will not listen to me.

Posted by: LP at March 26, 2006 07:31 PM

Give me a break. Pot causes schizophrenia? Alcohol. Now there's a problem drug. (Yes it is a drug)

Posted by: jake at July 31, 2007 01:02 AM

I think there are alot of factors that contribute to schizophrenia and excessive pot smoking my be one. Of course breathing the air and eating all the chemicals in food could very well be another. This planets going to hell in a bucket can't we at least enjoy the ride?

Posted by: traci mercado at July 31, 2007 02:29 AM

According to the study:

"Delta-9-THC (1) produced schizophrenia-like positive and negative symptoms; (2) altered perception; (3) increased anxiety; (4) produced euphoria; (5) disrupted immediate and delayed word recall, sparing recognition recall; (6) impaired performance on tests of distractibility, verbal fluency, and working memory (7) did not impair orientation; (8) increased plasma cortisol."

This sounds like they got realy high. Actually it is how anyone who has ever taken pot would described the symptons, with the exception that it doesn't mention the "munchies".

Posted by: me at September 1, 2007 06:34 AM

Since THC increases anxiety and alters perceptions, it also ruins relationships. Mine was destroyed by it.

Posted by: EM at September 26, 2007 09:17 AM

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