New Study Shows Marijuana Does Not Lower IQ, But Alcohol Does



Drunks make the best utilitarians


take that you useless pot!

I haven’t tried to look up the paper, but neither of the articles you linked to mention alcohol lowering IQ. They just say it was one of the factors the study controlled for when looking for an effect of marijuana use on IQ.

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The money quote is People often believe that using cannabis can be very damaging to intellectual ability in the long-term, but it is extremely difficult to separate the direct effects of cannabis from other potential explanations. Adolescent cannabis use often goes hand in hand with other drug use, such as alcohol and cigarette smoking, as well as other risky lifestyle choices. It’s hard to know what causes what- do kids do badly at school because they are smoking weed, or do they smoke weed because they’re doing badly? This study suggests it is not as simple as saying cannabis is the problem. (Of course anybody who attended an American High School after 1970 already knew that.)


Heavier cannabis users (at least 50 times by age 15) however, did show marginally impaired educational abilities. These children tended to have poorer exam results (3% lower) on compulsory school exams taken at age 16, even after adjusting for childhood educational performance, as well as alcohol, cigarette and other drug use.

Or it does.

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Well that explains some of the red-nosed members of congress.

I just spent several months on a research committee for The City Club of Portland analyzing Oregon’s Measure 91, which proposes legalizing marijuana. We recommended and the City Club adopted a Yes on the measure.

I think I did enough research to reply to this study. In 2012, the results of an extensive longitudinal study in New Zealand were published. This study demonstrated that there was an average of 8 point decline over time in IQ for people who started smoking MJ in their teens.

Simple common sense ought to tell us that applying mind altering drugs on a regular basis is likely to have a negative effect on a developing brain. Persistent regular use of any psychoactive chemical, legal or not, will almost certainly have a long term and probably negative effect on the human brain. In my short career as a musician, I witnessed a lot of musicians who were convinced that they were better when high. 99% of the time they were wrong.

I favor legalization of marijuana and, for that matter, most recreational drugs. However, it would be very very foolish for people to ignore the negative effects of psychoactive chemicals.


That’s not what it says at all. More the complete opposite if you are young and a weekly user.


[citation needed]

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