Cannabis is more "toxic" to teenagers' brains than to alcohol

Smoking cannabis has a greater impact on the adolescent brain than alcohol, with lasting effects on memory and reasoning, according to an international study.

Its "toxic" effect on the developing brain also significantly alters inhibitory control, which could explain, according to the authors, why early cannabis use is a risk factor for other addictions.

To protect the young brain, researchers at the Université de Montréal urged teenagers to postpone their cannabis use for as long as possible.

"Some of these effects are even more pronounced when (cannabis) use begins earlier in adolescence," said co-author and PhD student Jean-François Morin.

The researchers followed a sample of 3,826 Canadian teens over a four-year period to try to understand the relationship between alcohol, cannabis use and cognitive development in adolescents.

Adolescents from 31 different Canadian schools gave details of their drug and alcohol use patterns once a year.

Their brain skills have also been tested every year at school using computer-based cognitive tests.

In total, 28% of adolescents admitted to having used cannabis, compared to 75% who reported consuming alcohol at least occasionally.

Cannabis is more harmful than alcohol

The study found that brain vulnerability to cannabis and alcohol consumption in adolescence was associated with generally lower performance in all cognitive domains: recall memory, perceptual reasoning, inhibition and working memory.

Although alcohol use and drug use at a young age are known to cause learning, attention and decision-making problems, this study has shown that these problems are increasing as cannabis use increases. increased.

These effects have also been lasting, unlike those caused by alcohol consumption.

"Further increases in cannabis use, but not alcohol consumption, have shown additional simultaneous and delayed effects on cognitive functions, such as perceptual reasoning, recall memory, working memory and inhibitory control, "said Dr. Patricia Conrod, author and investigator, at the university newspaper.

"The finding that cannabis use was associated with lasting effects on a measure of inhibitory control, a risk factor for other addictive behaviors, may partly explain why early cannabis use is a risk factor for cannabis use. # 39; other addictions "added Morin.

Cannabis is considered the most widely used illicit drug in Australia

The 2016 National Household Drug Strategy Survey found that 35% of people aged 14 and over in Australia had used cannabis in their lifetime (6.9 million), compared to 10.4% in the last 12 months.

It can be addictive and its regular use has been associated with an increased risk of developing psychotic diseases such as schizophrenia, especially among adolescents.

The study is published in the American Journal of Psychiatry.