Posted on 10/07/2012 8:18:16 AM PDT by grayhog
Teens who smoke marijuana see their IQs drop as adults, and deficits persist even after quitting, according to a new study.
"The findings are consistent with speculation that cannabis use in adolescence, when the brain is undergoing critical development, may have neurotoxic effects," study researcher Madeline Meier of Duke University said in a statement.
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The study followed 1,037 New Zealand children for 25 years. Subjects took IQ tests at age 13, before any of them had smoked marijuana, and again at age 38. Throughout the study, participants also answered several surveys about their drug use.
Roughly 5 percent of the participants started using marijuana as teenagers. Those who smoked marijuana at least four times a week and used marijuana throughout their life saw their IQ drop an average of 8 points, the equivalent of going from an A to a B student. The drop was not explained by other drug use, years of education, schizophrenia or using marijuana in the day before the test.
People who eventually quit smoking pot still had lower IQs than they did at the start of the study.
Interestingly, people who picked up the habit as adults had no IQ drop, suggesting that marijuana may not be as harmful to the mature brain.
The findings are the first to associate intelligence declines with marijuana use. Past work linked low IQ and marijuana, but couldn't rule out the possibility that people who choose to smoke pot are inherently less smart than abstainers.
It's not clear why pot is bad for teen brains.
One possibility is that teenagers are more vulnerable to marijuana's effects on brain chemistry, said Susan Tapert, a neuropsychologist at the University of California, San Diego, who was not involved in the study.
During adolescence, neural connections are pruned in the hippocampus and the prefrontal cortex, critical regions for learning, memory and planning, Tapert said.
Those regions may also soak up the active ingredient in marijuana."A lot of the areas that are still developing during adolescent years happen to be the areas with high cannabis receptor density," Tapert told LiveScience.
But those who consistently smoke marijuana may simply make less intellectually stimulating choices at critical points in life.
"What people tend to do when they're under the influence is different than they would otherwise," Tapert said.
For instance, pot users may be less inclined to attend classes or do other activities that give the brain a workout. Getting off track early on can also limit future opportunities and thereby reduce IQ, she said.
Related: 10 Ways to Keep Your Mind Sharp
"Teens need to view cannabis as not an entirely benign compound, but as something that can impair your judgment and might not be great for your brain," Tapert said.
The study is detailed Aug. 27 in the journal Proceedings of the National Academy of Sciences.
I thought watching the debate Obama was looking down to read notes. But the hanky faux scandal revealed the no notes rule.
Really odd body behavior to look down for thirty minutes. Made him look to display an odd mixture of insecurity and disrespectfulness bordering on contempt.
The videos coming out a day or two before. Did they get to Obama? He’s very thin skinned.
Two of the four kids in my family were potheads or worse. My sister and I have excelled and are living our chosen version of the American Dream. My two brothers have always blamed others for their lesser existences, but I know what the real reason is. Dope is for dopes!
That is just so stupid, obama did not lose the debate because of the pot he smoked as a kid, it was because of the pot he smoked before he went on stage.
He be smokin' skunk afor it. Dat crap be hangin' on his clothes 'n' hair.
GMTA
(heh-heh)
Dunno if pot reduces your IQ.
But I believe reading the koran does.
I think the reason all the lib shows are suddenly on board with the pot story, is that actually he’s addicted to something much stronger than pot. Smokescreen.
On the other hand, Alcohol abuse causes 100% PROVEN PERMENENT BRAIN DAMAGE IN PEOPLE OF ALL AGES, but especially in kids. If I HAD to choose, I would rather have my kids smoke pot than binge drink. http://alcoholism.about.com/od/teens/a/blacer050216.htm
The other difference is that 95%+ of pot is sold by criminals who couldn't care less about selling to kids. 95%+ of alcohol/cigarettes are sold by legitimate businesses who can lose everything by selling to kids.
I work as a tutor for high school kids and every single one has told me pot is easier for them to buy than alcohol and cigarettes. Dealers don't card and don't care.
The intent of legalization is to have legitimate business for which carding can be enforced. Legitimate stores would take away the majority of the dealers’ customers and put them out of business.
Pot does very little damage to students compared to the damage inflicted by the US Department of Education.
I think the president is manic-depressive, and does take some kind of medication.
Don’t know if pot constricts or dialates the pupils, but the bright stage lights I’ll bet had a lot to do with the looking down. IMHO
Constricts, dilating would open them to allow more light, that’s why when they dilate your eyes at the doctor you are given those stupid paper sunglasses, the light is painful.
"I started using drugs because I wanted to fit in, but I continued to use
them because I got hooked on the sensation of losing contact with reality."
It's a good thing he's got Valerie Jarett to wipe the coke off his nose and plug the Teleprompters in for him everyday.
LOL!
I think it has more to do with the policy of Western governments who pay stupid people to breed.
How about he is just inept & was never smart enough to be prez!
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