January 20, 2005

Marijuana and Schizophrenia News

25% of cannabis users faces a tenfold higher risk of mental illness

Jenny Hope, the medical correspondent in the British Newspaper "The Daily Mail", reported today on research which suggests that 1 in 4 cannabis users faces a tenfold higher risk of mental illness due to their genetic profile.

The researchers, led by Professor Avshalom Caspi of the Institute of Psychiatry in London, will publish their study in the journal Biological Psychiatry. They investigated whether susceptibility to psychosis triggered by cannabis could be linked with a particular gene, known as COMT, which makes people more prone to schizophrenia. COMT is involved in the breakdown of dopamine in the brain, and has two variants, or alleles, called val and met. The val allele has been linked with the risk of schizophrenia.

Research showed that those with two forms of the val allele were 10.9 times more likely to develop psychosis following cannabis use.

Source: The British Medical Journal Daily Health Alerts


can someone help me? ive used it like 4 times and my mom has schizophrenia. what the hell am i going to do

Posted by: tatyana at January 16, 2006 07:38 PM

Avoid it in the future, and focus on doing well in school (and having good relationships with friends) - and don't stress too much, and you'll likely do fine. See the list of information on causes and prevention on our web site.

Posted by: szadmin at January 16, 2006 08:29 PM

My son has smoked marijuana heavily since he was fourteen. He is now 19 and is showing strong symptoms of schitzophrenia. He continues to smoke marijuana. His uncle has been diagnosed with the disorder as well and smoked marijuana heavily as a teen. He began to show signs of this as well at the same age. I cannot find any studies on the brains ability to heal if marijuana use is curtailed. Can you help me?

Posted by: hollister baxter at May 26, 2006 08:16 PM

I have a son who is 17 and has been diagnosed with cannibus psychosis and schizotype personality. He continues to smoke marijuana and he refuses to acknowlege how much harm he is doing to himself. please help.

Posted by: elizabeth at June 10, 2006 06:16 AM

I smoked marijuana a lot as a teenager and early adult. There are many problems with marijuana beyond schizophrenia. It also alters the hippocampus which is involved in learning. I don't know whether this is longterm or not. But, the fact that I was high for a large majority of my teenage years means that I am a serious disadvantage when compared to others. I feel like I could be on a higher level both academically and creatively. Perhaps, you folks can tell your kids that they are dehibilating themselves.

Posted by: Joe at July 16, 2006 06:44 AM

Hi. My boyfriend smokes. I dont really like it but he does it with all of his friends because it "chills him out". I have known him since elementary school and he used to have major emotional problems. He just couldnt control his emotions at all and his family life was tough. After he began to smoke, he became better at controlling his emotions but he focused less on school and more on friends. When we started dating he quit for a while to bring up his grades. He has started smoking again and is doing a pretty good job keeping his grades up in harder classes that he chose to take. I am just worried about him because hes been smoking since he was 13 and he seems to be a bit lazy about important things- like work-at times to me. What would your advice for him be?

Posted by: susan at January 4, 2007 07:11 AM

Although these studies have been proven by these doctors people also have to remember that if you have a mental illness in your family you are more likely to get it to just because its in the blood line, and i dont see why everybody is all of a sudden so concerned with the consequences of it. theres consequences to everything just like with alcohol which is a WAY bigger health issue than weed. Theres probably a 90 percent chance that your child has used other drugs besides marijuana and thats why their in the situation that their in.

Posted by: sadiez at May 1, 2007 11:53 AM

I think that marijuana is a serious problem, because according to the science studies it seems that cannabis use can precipitate schizophrenia in vulnerable individuals (alcoholism, undernutrition…), especially. However, there are other studies about the opposite marijuana effect, so scientists say; „One possibility is that there are good guys and bad guys within cannabis… Maybe the cannabidiol ameliorates some of the effects of the THC and maybe it actually might be good for you if you are psychotic“. I would like to show that there can be a "nutritional theory" (different „body calcium status“ in good and bad guys…) about the cause of schizophrenia based on "calcium deficiency". The goal of my comments is to show that cannabis use can be a cause of schizophrenia; characterize two effects on NMDA hypofunction, related to schizophrenia-associated neurodegenerative impairment. See also website www.bse-expert.cz , chapter; Hyperfunction (Alzheimer’s disease and Parkinson disease) and hypofunction (schizophrenia) of glutamatergic neurons. See also my opinion- article in Medical News Today

Posted by: Josef Hlasny at June 21, 2007 10:23 AM

My grandmother suffered from severe schizophrenia, developing it in her early 20s.
I'm 18 and have been smoking weed consistently (about once a week) for a year and a half. Although I became physically ill and mildly addicted to a stimulant I used to abuse, I've never suffered from any lasting physical effects of marijuana; I've always been terrified of developing schizophrenia. Are there any brain scans or behavioral tests I can have performed to determine if my liklihood to develop it is any stronger than say, my siblings who are also genetically predisposed? Also, is the evidence strongly, or only kind of, in favor of my quitting altogether? Would just decreasing the frequency of my usage help?

Posted by: name at January 1, 2008 11:41 PM

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