July 1, 2003 -- Long-term and even daily marijuana use doesn't appear to cause permanent brain damage, adding to evidence that it can be a safe and effective treatment for a wide range of diseases, say researchers.
The researchers found only a "very small" impairment in memory and learning among long-term marijuana users. Otherwise, scores on thinking tests were similar to those who don't smoke marijuana, according to a new analysis of 15 previous studies.
In those studies, some 700 regular marijuana users were compared with 484 non-users on various aspects of brain function -- including reaction time, language and motor skills, reasoning ability, memory, and the ability to learn new information.
"We were somewhat surprised by our finding, especially since there's been a controversy for some years on whether long-term cannabis use causes brain damage," says lead researcher and psychiatrist Igor Grant, MD.
"I suppose we expected to see some differences in people who were heavy users, but in fact the differences were very minimal."
The marijuana users in those 15 studies -- which lasted between three months to more than 13 years -- had smoked marijuana several times a week or month or daily. Still, researchers say impairments were less than what is typically found from using alcohol or other drugs.
"All study participants were adults," says Grant, professor of psychiatry and director of the Center for Medicinal Cannabis Research Center at the University of California, San Diego School of Medicine.
"However, there might be a different set of circumstances to a 12-year-old whose nervous system is still developing."
Analysis of Studies Finds Little Effect From Long-Term Use
By Sid Kirchheimer
WebMD Health News
Re: WebMD says Marijuana is nontoxic and does NOT cause brain damage from longerm use
Please note that the way we post news has changed, because of our main news page. You can find the full instructions here.
The most important changes are:
Articles are no longer posted in quotes.
The introduction of the article should be in bold.
Images should be added if possible and placed in the article, following the instructions linked to above and here.
Information about the article, like link, author, date should be posted below the article.
Your personal comments about the article can be posted either in quotes at the end of the article or in a separate post.
The news forums may contain news articles only.
Please be so kind to review your articles and correct this.
Further it may be good to know that recent articles with the highest thread ratings show up on the main news page. So without ratings, many people will not see it. So please rate news treads.
The main news page is accessible from the tabs on the top of any DF page.
15-01-2009, 20:43
Hybrid Mode
