Ok, you probably are thinking, what’s new about that?
A recent study released by the Canadian Medical Association Journal (CMAJ) broke down changes in IQs by pot usage; namely, those who would be considered heavy smokers (5 joints or more a week) showed an appreciably dip in their IQs.
The pool study consisted of 70 young adults with urinalysis results, self-reports of marijuana use and a broad measure of IQs obtained at both a preteen (9–12 years) and a young adult (17–20 years) assessment.
While the finding that heavy use of the drug led to lower IQs isn’t necessarily surprising–the other result might be. Those with minimal or occasional use actually saw an increase in their IQs. But that was pretty much the case with non-users as well. Which researchers deduced meant that there is a certain point when continual use of the drug takes its toll on one’s ability to think.
The study also showed that IQ has little to do with whether or not someone will start smoking weed. Researchers used the preteen IQ scores before any marijuana use to deduce this and concluded that how smart you are (or aren’t) isn’t a predictor of future marijuana use.