The European College of Neuropsychopharmacology recently presented their findings in regards to moderate marijuana use by young people and their IQ level at an event in Berlin, Germany.
Over 2,500 participants had their IQ tested at the age of 8 and again at the age of 15. The results found by the University College of London showed that there was no correlation between marijuana use and lower IQ in the 15 year old subjects. The study’s author stated that, “In particular, alcohol use was found to be strongly associated with IQ decline. No other factors were found to be predictive of IQ change.”
The lead author of the study was even quoted in the Independent Business Times as saying, “Our findings suggest cannabis may not have a detrimental effect on cognition, once we account for other related factors particularly cigarette and alcohol use. This may suggest that previous research findings showed poorer cognitive performance in cannabis users may have resulted from the lifestyle, behavior and personal history typically associated with cannabis use, rather than cannabis use itself.”
There is also the argument of whether kids begin doing poorly in school as a result of marijuana use or for other reasons. Regardless, it appears that marijuana use doesn’t have any long term negative impacts on brain development in adolescents.