Heavy pot smokers shrinking their brains

June 13, 2008 at 6:53 am (Uncategorized) (, , , , , , , )

Australian researchers have found that long-term heavy use of marijuana may cause parts of the brain to shrink.

Published in this month’s Archives of General Psychiatry, the study found that the hippocampus and amygdala were smaller in men who were heavy marijuana users compared to non-users.

The study looked at 15 men heavy marijuana users, who had smoked at least five marijuana cigarettes daily for on average of 20 years.

Brain scans showed that on average their hippocampus volume was 12% less and amygdala volume was 7% less than in the 16 men who were not marijuana users.

The hippocampus regulates memory and emotion, while the amygdala plays a critical role in fear and aggression.

“These findings challenge the widespread perception of cannabis as having limited or no harmful effects on (the) brain and behaviour,” says Dr Murat Yucel of ORYGEN Research Centre and the University of Melbourne, who led the study.

The researchers also found heavy cannabis users earned lower scores than non-users in a verbal learning task – trying to recall a list of 15 words.
Psychotic disorders

The users were more likely to exhibit mild signs of psychotic disorders, but not enough to be formally diagnosed with any such disorder, the researchers say.

“Like with most things, some people will experience greater problems associated with cannabis use than others,” Yucel says.

“Our findings suggest that everyone is vulnerable to potential changes in the brain, some memory problems and psychiatric symptoms if they use heavily enough and for long enough.”

While about half of the marijuana users reported experiencing some form of paranoia and social withdrawal, only one of the non-users reported such symptoms, Yucel says.

The heavy marijuana users, average age 40, said they had used other illicit drugs less than 10 times.

The researchers acknowledged that the study’s findings could not be completely attributed to marijuana use.

But Yucel says the findings certainly suggested marijuana was the cause.

He says the researchers have begun new research on the effects of short-term, long-term, moderate and heavy use of marijuana.

Will Dunham

A. says: Hey man, drinking alcohol makes you lose braincells and we’ve been doing that for years, so why all the worry? Why not light up, switch on the TV and grab a bucket of popcorn. F**k it, it’s only your brain, right?





  1. jsknow said,

    Anyone that knows anything about pot can easily debunk ALL the claims about the harms. Where are all the sick pot smokers? Where are all the people with tiny little brains that have shrunk from smoking pot? Where is the gateway that no more pot smokers travel through than any other group of the general population? PROHIBITION never works it CAUSES CRIME & VIOLENCE. Illegal drugs are easier for kids to get. The USA spends $69 billion a year on the drug war, builds 900 new prison beds and hires 150 more correction officers every two weeks, arrests someone on a drug charge every 17 seconds, jails more people than any nation and has killed over 100,000 citizens because of the drug war. It’s time to remove ALL the politicians that promote prohibition. Everyone should DEMAND their Constitutional rights be honored. The right; to freedom of religion, free speech, a free press, to keep and bear arms, to be secure in your person, house, papers and effects against unreasonable search and seizure, to life, liberty and property, to be protected from having your property taken by the government without due process of law and without just compensation, to confront the witnesses against you, to be protected from excessive bail, excessive fines, cruel and unusual punishment, to vote and many others have been denied to millions of Americans in the name of the drug war. It’s time to take action. JOIN THE EMAIL LIST, COMMENT ON THE BLOG AND WATCH THE VIDEOS ON THIS WEBSITE:
    Internet Explorer: http://jsknow.angelfire.com/home
    Other Browsers: http://jsknow.angelfire.com/index.html

  2. azumuth said,

    I know that, that’s why I published the blog. I’m not for prohibition and never have been.

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