A study published Wednesday in the American Journal of Psychiatry is shedding new light on the changing relationships between adolescents’ substance use and their cognitive development. And it may even overturn some common assumptions about the relative risks posed to young people by alcohol and cannabis. Legalization advocates often present cannabis as a relatively safer substance than alcohol. It’s a claim that most research on adults supports. But the reality is significantly less clear when it comes to the two substances’ impact on developing brains. Indeed, researchers in Quebec are suggesting the reverse, that cannabis is more deleterious on young minds than alcohol.
Cannabis Impacted Teens’ Cognitive Ability More Than Alcohol, Researchers Say
Headed up by lead author Patricia J. Conrad, researchers with the University of Montreal tracked 3,826 Montreal teens’ alcohol and cannabis use over four years, beginning in the seventh grade, at age 13. The study’s sample size represents students across 31 different schools and 5 percent of all students entering high school in the 2012-2013 academic year in the Greater Montreal area.
Researchers assured student participants that parents and teachers would not have access to their self-reported data on cannabis and alcohol use. And over the four year period, participants performed tasks that measured their cognitive development. The study collected data on recall and working memory, perceptual reasoning and inhibition using computerized assessments.
The study, titled “A Population-Based Analysis of the Relationship Between Substance Use and Adolescent Cognitive Development,” then ran the data through models to determine participants’ vulnerability to cognitive effects, the duration of short-term and long-term effects, and how age influenced their development.
As they expected, researchers detected commonalities between vulnerability effects on cognition for both alcohol and cannabis across