Today it’s feasible to say that about half of Americans use cannabis at least one time in their lifetime, and several are known to start young. However, there have been studies that assert that the drug could impair the development of the adolescent brain, the real liability is questionable and being disputed. Now, for the first time ever, scientists conducted a study where they investigated the overall effects of long-term marijuana use in teens.
The largest ever long-term twin study, comprising of more than 3,000 adolescents from around the world, has found little evidence to support the theory that adolescent or teen marijuana use has any direct effect on intellectual decline.
In order to find these results, they contrasted IQ developments in twin siblings who either smoked or refrained from smoking marijuana for over a span of 10 years. Making sure to take environmental circumstances into account, the scientists discovered no significant correlation between marijuana use and lower IQ.
The observed connection between diminishing brain power and marijuana use can be accredited to a 2012 study done by Duke University researchers, who came to the conclusion that continuous and excessive marijuana use is most likely related with a decline in IQ.
However, a follow-up study that was also published in the Proceedings of the National Academy of Sciences – affirmed that many unmentioned factors have also been linked to IQ decline. Examples includes cigarette and alcohol use, low socio-econimc status, and mental illness, were never taken into account in other studies.
One report, known as the the Risk Factors for Antisocial Behavior (RFAB) study from Southern California, measured the IQ of 789 twins aged of 9-10 years in 2001, then tested them again on five separate occasions over the course of the next 10 years. The Minnesota Twin Family Study (MTFS) traced 2,277 teenaged twins, testing them once in 1990-1996 when they were 9 -11 years old, and again in 1999-2006.
“We also examined a subset of discordant twin pairs in which one sibling had never used marijuana before and the cotwin had frequently used marijuana (i.e., greater than 30 lifetime uses and/or a period of daily use),” the researchers report in Proceedings of the National Academy of Sciences.
Although there is still a general opinion that smoking pot makes you more than slightly stupid, there really isn’t much concrete valid evidence or data to stand behind the allegation. And now many universities all over the country have researchers analyzing the findings of two previous reports that investigated the relationship between marijuana use and intelligence decline in twins, and found no measurable link either.
No matter the many different methods, the studies reach the same conclusion: They found no evidence that adolescent marijuana use leads to a decline in intelligence. Yes, marijuana is a “drug”. Of course like any other drug — alcohol, nicotine, caffeine — there will always be risks and benefits that come with use. But fabricating the overall scope of those risks and benefits won’t help promote the creation of more sophisticated policies. The proof is in the pudding my friends, all you have to do is take a look at the history of the drug war.