Both alcohol and cannabis misuse is linked with impaired mental functioning. Understanding the impact of substance use is particularly important when studying the developing brain.
A recent piece of research, published in the American Journal of Psychiatry, has investigated the relationship between year-to-year cognitive development and the impact of substance use. The study, which involved over 3800 adolescents from 31 schools in Montreal, gathered data concerning substance use and different aspects of cognitive functioning over the course of 4 years.
It was revealed that 75% of the teenagers disclosed they drank alcohol at least occasionally and 28% of the teenagers admitted to some kind of cannabis use.
Results found that the teenagers who were more likely to use cannabis or alcohol showed lower working memory, perceptual reasoning, and inhibitory control. The research also highlighted that cannabis use, compared to alcohol use, was particularly associated with negative long term consequences on adolescent cognitive functioning.
One biological explanation provided by the researchers is that cannabis has a permanent neurotoxic impact on mental activity.
These findings stress the importance of protecting youths from the lasting adverse impact of substance use.