Pot Doesn't Cause Permanent Brain Damage

Pot Doesn't Cause Permanent Brain Damage
From UC San Diego News Release

Researchers Find Minimal Long-Term Effects of Marijuana Use
An analysis of research studies with long-term, recreational users of marijuana has failed to reveal a substantial, systematic effect on the neurocognitive functioning of users. According to researchers at the University of California, San Diego (UCSD) School of Medicine, the only deleterious side effect found was a minimal malfunction in the domains of learning and forgetting.
The findings were particularly significant considering the movement by several states to make cannabis (marijuana) available as a medicinal drug, and questions regarding its potential toxicity over long-term usage.

Published in the July issue of the Journal of the International Neuropsychological Society, the study involved a quantitative synthesis of 15 previously published research studies on the non-acute (residual) effects of cannabis on the neurocognitive performance of adult human subjects.

The studies included 704 long-term cannabis users and 484 non-users. The neurocognitive performance measurements included simple reaction time, attention, verbal/language, abstraction/executive functioning, perceptual/motor skills, motor skills, learning and forgetting.

"Surprisingly, we saw very little evidence of deleterious effects. The only exception was a very small effect in learning new information," said Igor Grant, M.D., the study's senior author, a UCSD professor of psychiatry, and director of the Center for Medicinal Cannabis Research (CMCR), a collaborative, state-supported program between UCSD and UC San Francisco, that oversees 11 studies of the safety and efficacy of medicinal cannabis to treat certain diseases.

In describing the negative effects in the study, the research team said the problems observed in learning and forgetting suggest that chronic long-term cannabis use results in selective memory defects. They added that "while the results are compatible with this conclusion, the effected size for both domains was of a very small magnitude."

Grant added that the minimal side effects seen "raised the question of practical significance. If we barely find this tiny effect in long-term heavy users of cannabis, then we are unlikely to see deleterious side effects in individuals who receive cannabis for a short time in a medical setting."

In addition, Grant said that heavy marijuana users often abuse other drugs, such as alcohol and amphetamines, which also might have long-term neurological effects. This raises the question of the extent to which the other drugs contributed to the minimal problems found in learning and forgetting in the marijuana users.

The paper's authors also noted that many of the research studies examined had significant limitations, either with small numbers of subjects or insufficient information about potential confounding factors, such as exposure to other drugs or presence of neuropsychiatric factors such as depression or personality disorders.

They noted that only studies that begin with the examination of children and young adolescents before they enter the period of risk to cannabis exposure, can sufficiently reduce the influence of these additional factors.

In addition to Grant, the paper's authors included doctoral students Raul Gonzalez, M.S., and Catherine L. Carey, M.S. and Loki Natarajan, Ph.D., UCSD HIV Neurobehavioral Research Center (HNRC) and UCSD Department of Family and Preventive Medicine, and Tanya Wolfson, M.A., UCSD HNRC.



http://alcoholism.about.com/cs/pot/a/blucsd030628.htm




We know it ain't vitamins people.... but it does not make you stupid. Increased risk of cancer = yes, like alcohol and tobacco but not as harmful.

http://www.webmd.com

Heavy Marijuana Use Doesn't Damage Brain

Analysis of Studies Finds Little Effect From Long-Term Use By Sid Kirchheimer
WebMD Medical News Reviewed By Michael Smith, MD
on Tuesday, July 01, 2003

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.


Surprising Finding


"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."


10 States OK Marijuana Use


Grant's analysis, published in the July issue of the Journal of the International Neuropsychological Society, comes as many states consider laws allowing marijuana to be used to treat certain medical conditions. Earlier this year, Maryland became the 10th state to allow marijuana use to relieve pain and other symptoms of AIDS, multiple sclerosis, cancer, glaucoma, and other conditions -- joining Alaska, Arizona, California, Colorado, Hawaii, Maine, Nevada, Oregon, and Washington.


Medicinal marijuana is available by prescription in the Netherlands and a new marijuana drug is expected to be released in Great Britain later this year. In the U.S. and elsewhere, Marinol, a drug that is a synthetic form of marijuana and contains its active ingredient, THC, is available by prescription to treat loss of appetite associated with weight loss in AIDS patients.


Grant says he did the analysis to help determine long-term toxicity from long-term and frequent marijuana use. His center is currently conducting 11 studies to determine its safety and efficacy in treating several diseases.


"This finding enables us to see a marginal level of safety, if those studies prove that cannabis can be effective," Grant tells WebMD. "If we barely find this effect in long-term heavy users, then we are unlikely to see deleterious side effects in individuals who receive cannabis for a short time in a medical setting, which would be safer than what is practiced by street users."


Grant's findings come as no surprise to Tod Mikuriya, MD, former director of non-classified marijuana research for the National Institute of Mental Health Center for Narcotics and Drug Abuse Studies and author of The Marijuana Medical Handbook: A Guide to Therapeutic Use. He is currently president of the California Cannabis Medical Group, which has treated some 20,000 patients with medicinal marijuana and Marinol.


'Highly Effective Medicine'


"I just re-published a paper of the first survey for marijuana toxicity done in 1863 by the British government in India that was the most exhaustive medical study of its time in regards to possible difficulties and toxicity of cannabis. And it reached the same conclusion as Grant," Mikuriya tells WebMD.


"This is merely confirming what was known over 100 years ago, as well as what was learned by various government findings doing similar research -- marijuana is not toxic, but it is a highly effective medicine."


In fact, marijuana was available as a medicinal treatment in the U.S. until the 1930s.


Lester Grinspoon, MD, a retired Harvard Medical School psychiatrist who studied medicinal marijuana use since the 1960s and wrote two books on the topic, says that while Grant's finding provides more evidence on its safety, "it's nothing that those of us who have been studying this haven't known for a very long time.


"Marijuana is a remarkably safe and non-toxic drug that can effectively treat about 30 different conditions," he tells WebMD. "I predict it will become the aspirin of the 21st century, as more people recognize this."


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SOURCES: The Journal of the International Neuropsychological Society, July 2003. Igor Grant, MD, professor of psychiatry, University of California, San Diego School of Medicine; director, UCSD Center for Medicinal Cannabis Research Center. Tod Mikuriya, MD, president, the California Cannabis Research Medical Group, Oakland; former director of non-classified marijuana research, the National Institute of Mental Health Center for Narcotics and Drug Abuse Studies. Lester Grinspoon, MD, professor emeritus of psychiatry, Harvard Medical School, Boston; author, Marijuana: The Forbidden Medicine and Marihuana Reconsidered.

wow someone loves pot

Oh yeah! Giggity Giggity Giggity

you don't even know.......

Well then smoke weed and be marry! just dont expect the government to legalise ur hapiness anytime soon

I do expect them to. It makes all the social, ecological and economic sense in the world!

Hev, don't you just love when people make a claim, tell you you have no proof for your argument, you give your proof, and then they have no backing for their side of the argument at all?

Pot will be legal one day.

of course it makes sense to you, you need to get more pot heads elected to office.....birds of a feather

Drugs are drugs all of them deplete brain cells and cause health problems. They all cause addiction, even weed. Why legalize weed and not lsd. They both make you see things that are not there. What classifies one as more dangerous as the other.