Cannabis advocates like to believe that the drug is a safe alternative to alcohol – but a new study found cannabis is actually worse for teenage brains.
The researchers followed 3,826 teenagers from age 12 to 15, measuring their drug and alcohol use and their performance at school and in cognitive test.
Both alcohol and cannabis damage the development of teenagers, the researchers found – but cannabis is worse.
Dr. Patricia Conrod, from the Department of Psychiatry at Université de Montréal, said, ‘very few studies are designed to look at this question from a developmental perspective.
‘Our study is unique in that it followed a large sample of high school students using cognitive and substance-use measures. Using this big-data approach, we were able to model the complex nature of the relationship between these sets of variables.’
The researchers found that both alcohol and cannabis use had a negative impact on cognitive functions such as memory and decision-making.
Conrod said, ‘Further increases in cannabis use, but not alcohol consumption, showed additional concurrent and lagged effects on cognitive functions, such as perceptual reasoning, memory recall, working memory and inhibitory control.
‘Of particular concern was the finding that cannabis use was associated with lasting effects on a measure of inhibitory control, which is a risk factor for other addictive behaviours, and might explain why early onset cannabis use is a risk factor for other addictions.’