A recent study comparing marijuana use and IQ scores showed no real link between a lower IQ and the use of weed in teens. The use of twins in this study, which was done over a significant amount of time, was able to debunk the theory that there is a correlation between pot smoking and a lower IQ.
According to News Max on January 20, this study used twin siblings, where one abstained from marijuana over a 10-year-period and the other used marijuana during that time. The conclusion of this research was that there was no measurable difference in their IQ scores.
The study was published today in the Proceedings of National Academy of Sciences and the findings may help put to bed the theory that pot use lowers you intellect level. Researchers from the University of Southern California followed a large group of teen drug users for an extended period of time, reports MSN News.
The lead researcher on this study, Nicholas Jackson, said that most studies that linked weed to memory loss and lower IQ scores did not represent the use of marijuana over time. Many of those studies were just “single snapshots” in time and not representative of an impact that weed has on IQ over time.
The use of marijuana during adolescence when the brain is still developing was thought to have caused a “poorer neurocognitive outcome.” In other words, some scientists believed that pot smoking in your teens stunts your brain development in certain areas.
The report coming from this study stated:
“Marijuana users had lower test scores relative to nonusers and showed a significant decline in crystallized intelligence between preadolescence and late adolescence,” which is what the PNAS study stated in its abstract. This was also explained by the researchers that this was not necessarily the result of pot use, as some theories state.
“However, there was no evidence of a dose-response relationship between frequency of use and intelligence quotient (IQ) change. Furthermore, marijuana-using twins failed to show significantly greater IQ decline relative to their abstinent siblings.”
“Evidence from these two samples suggests that observed declines in measured IQ may not be a direct result of marijuana exposure but rather attributable to familial factors that underlie both marijuana initiation and low intellectual attainment.”
This isn’t the only recent study to suggest that the theory of pot use linked to a lower IQ is without basis. Another study published Jan. 6 in the Journal of Psychopharmacology stated that “modest cannabis use in teenagers may have less cognitive impact than epidemiological surveys of older cohorts have previously suggested.”