Clinical Psychopharmacology Unit


How does cannabis use affect teenagers' brains, cognitive functions and psychological well-being?











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Team: Prof Val Curran, Dr Tom Freeman, Dr Claire Mokrysz, Dr Will Lawn and Rachel Lees

Across the globe, more people use cannabis than any other illicit drug, and roughly half of them start using it in before they are 18 years of age. There is concern that starting cannabis use at a young age may lead to increased risks of addiction, mental health issues, cognitive impairment, poorer educational achievement and disrupted adolescent brain development. In addition, the strength of cannabis has increased dramatically over recent years, so very high potency varieties (15% THC or more) are what most teenagers get when they start using. The high potency varieties also contain virtually no cannabidiol (CBD) - an ingredient in cannabis which may protect adults against some of the harms caused by THC.

In a series of three related studies, cannTEEN aims to find out how the use of cannabis affects the brain, cognitive function and psychological well-being, comparing teenagers and adults. The project is funded by the UK Medical Research Council (MRC).

Study 1 will determine how cannabis use over a 12 month period affects psychological well-being, cognitive function and markers of endocannabinoids in teenagers and adults. Study 2 will determine the extent to which there are differential changes in brain structure and function in teenage and adult cannabis users over this same 12 month period. Study 3 will be the first experiment to examine the causal effects of different types of cannabinoids on the adolescent brain.

Although virtually all cannabis users experience at least transient cognitive impairments, only around 9% of adults become addicted and a smaller minority ever develop psychosis. We will also analyse our data to address this question: what factors predict vulnerability/resilience to the negative consequences of use and do these differ in teenagers and adults?

Crucially, this project will enhance our theoretical and clinical understanding and provide vital information to young cannabis users, to their families, friends and those professionals who interact with them.

If you would like to hear more about the study, or if you would like to take part, please email Claire, Will & Rachel at pals.cannteen@ucl.ac.uk


Medical Research Council