Home > Cannabis has 'more lasting effect on teenage brains than alcohol'.

[NHS Choices] (2018) Cannabis has 'more lasting effect on teenage brains than alcohol'. London: NHS Choices.

URL: https://www.nhs.uk/news/pregnancy-and-child/cannab...

"Cannabis 'more harmful than alcohol' for teen brains," reports BBC News. Canadian researchers investigated the links between alcohol and cannabis use and performance on various tests of brain function in 3,826 school pupils over 4 years, starting at age 12 to 13. They found teens who used cannabis performed less well, especially in tests of memory and impulse control. The researchers said teenagers with worse memory and impulse control were more likely than other teens to use alcohol and cannabis. However, an increase in cannabis use in 1 year was associated with lower test scores that year and also in the following year, suggesting that cannabis could have a lasting effect on their brain function. The researchers did not find this result in teens using alcohol. Cannabis also seemed to have greater effects in younger teens compared with older teens.


This study will add to the body of research assessing the potential cognitive and mental health effects of cannabis. As is often the case with such research, it's difficult to determine whether cannabis directly causes these effects or whether people at risk of cognitive or mental health problems may be more likely to use cannabis. We do know that the brains of teenagers are still developing, so any drug or substance that can affect the brain, be it illegal or legal, could possibly have long-term effects. There are also a number of health risks relating to cannabis use. Read more about how cannabis can lead to health problems.


Where did the story come from?

The researchers who carried out the study were from the University of Montreal, Centre Hospitalier Universitaire Sainte-Justine and Dalhousie University in Canada. It was funded by the Canadian Institutes of Health and published in the peer-reviewed journal The American Journal of Psychiatry. The study was widely reported in the UK media. The media reports were broadly accurate but the headlines tended towards scaremongering. The Sun referred to cannabis as "brain rot" while the Mail Online implied the results lasted into adult life – which we do not know, as students were not followed up beyond age 16 to 17………

Item Type:Evidence resource
Publication Type:Report
Drug Type:Cannabis
Intervention Type:AOD disorder, AOD prevention, AOD disorder harm reduction
Source:NHS Choices
Date:4 October 2018
Publisher:NHS Choices
Place of Publication:London
Subjects:A Substance use, abuse, and dependence > Effects and consequences
B Substances > Cannabis / Marijuana
F Concepts in psychology > Skills
F Concepts in psychology > Learning
G Health and disease > State of health
G Health and disease > Substance related disorder > Substance related mental disorder
T Demographic characteristics > Adolescent / youth (teenager / young person)
VA Geographic area > United States

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