A single dose of cannabis could harm the cognitive development of adolescents
A single dose of cannabis could potentially affect the cognitive development of adolescents, warns a new study at the University of Montreal.
Dr. Patricia Conrod and her colleagues took an interest in the alcohol and cannabis use of some 4,000 young people who entered high school in the greater Montreal area in 2012 and 2013. Their consumption was measured and their cognitive functions assessed at using computer tests every year for four years.
The size of the cohort allowed researchers to use sophisticated computer models to study the relationship between substance use and cognitive function.
Their conclusion is both simple and startling: the younger a person consumes cannabis, the more his cognitive functions are diminished.
“The relationship is specific to cannabis,” said Dr. Conrod. No additional effects related to alcohol were detected on cognitive functions. At this time, there is no reason to believe that there is a safe level of consumption for teens. ”
Many cognitive functions are affected by cannabis, she added: memory recall, working memory, inhibitory control, logic and problem solving were all affected.
The level of inhibitory control of fourth-graders who were habitual users of cannabis was the same as that of first-graders who had never used cannabis. “In other words, ordinary cannabis users had lost three years of cognitive development at certain levels,” said the researcher.
“Inhibitory control and working memory are very important functions that are involved in adult decision-making, self-control and behavioral control,” said Dr. Conrod. They are also involved in addictive behaviors. ”
Researchers also detected a long-term effect of cannabis use, that drinking in a given year appeared to interfere with cognitive function the following year.
Is it necessary to deduce that a single smoked joint this year could have consequences until next year?
“We have not measured it, but right now it’s really, really not impossible,” said Dr. Conrod. Other studies suggest that even low THC exposure during adolescence can interfere with brain development. ”
The findings of this study were presented at a conference of the Canadian Association of Neuroscience.