Article by Udem Nouvelles, Universite de Montreal
The more teenagers delay smoking marijuana until they’re older, the better it is for their brains, but there may be little ill effect if they start after age 17, says a new Université de Montréal study.
Adolescents who smoke pot as early as 14 do worse by 20 on some cognitive tests and drop out of school at a higher rate than non-smokers, confirms the study, published Dec. 29 in Development and Psychopathology, a Cambridge University Press journal.
“Overall, these results suggest that, in addition to academic failure, fundamental life skills necessary for problem-solving and daily adaptation […] may be affected by early cannabis exposure,” the study says.
However, the cognitive declines associated with cannabis do not seem to be global or widespread, cautioned the study’s lead author, Natalie Castellanos-Ryan, an assistant professor at UdeM’s School of Psychoeducation.
Her study found links between cannabis use and brain impairment only in the areas of verbal IQ and specific cognitive abilities related to frontal parts of the brain, particularly those that require learning by trial-and-error.
In addition, if teenagers hold off until age 17 before smoking their first joint, those impairments are no longer discernible. “We found that adolescents who started using cannabis at 17 or older performed equally well as adolescents who did not use cannabis,” said Castellanos-Ryan.