Teenagers who consume cannabis are no more likely to experience symptoms of poor mental health, but may be at greater risk of developing a cannabis addiction, a new study by UCL and King’s College London has found.
The study, published in the Journal of Psychopharmacology, suggests that adolescents who used cannabis were no more likely to have higher levels of subclinical depression or anxiety than adults who use cannabis, nor were they more vulnerable than adult users to experience psychotic-like symptoms.
The study involved 274 participants, including 76 adolescents aged 16 and 17, who used cannabis one to seven days per week, alongside similar numbers of adult cannabis users aged 26-29. All participants answered questions about their cannabis use over the last 12 weeks and responded to questionnaires commonly used to assess symptoms associated with poor mental health.
Participants who consumed cannabis on average used it four times per week. The study found that adolescent cannabis users were three and a half times as likely to develop severe cannabis use disorder than adult users. Adolescents may be more vulnerable to cannabis addiction because of factors such as increased disruption to relationships with parents and teachers, a more malleable brain and developing endocannabinoid system as well as a more fluid sense of identity and shifting social life.
Cannabis use disorder is defined by symptoms such as cravings, cannabis use contributing to failures in school or work, heightened tolerance, withdrawal symptoms, interpersonal problems caused by or exacerbated by cannabis use or intending to cut back consumption without success.
Speaking to leafie, Ian Hamilton, Associate Professor of addiction welcomed the study, but believes it may have overlooked an important factor: “It is encouraging to see more research into cannabis dependency as we still know relatively little about this aspect of exposure to cannabis. Although the authors report increased rates of dependency in adolescents compared to adults they have not accounted for combined tobacco and cannabis use.
“As many adolescents include tobacco in a cannabis joint it is difficult to know what they have become dependent on. We do know that tobacco is more addictive than cannabis so it is likely that any symptoms of dependence and or withdrawal are related to tobacco rather than cannabis.”
Studies have shown that legalising cannabis can lead to reduced consumption among young people. A 2021 study published by the Journal of the American Medical Association found that opening controlled recreational and medical cannabis markets can lower consumption among adolescents. Similar results were found in a Government-funded study by the University of Michigan, which showed a significant reduction in cannabis consumption in 8th-12th grade students post legalisation.
“Even if cannabis were to be regulated teenagers would still be able to access cannabis via the black market.” Professor Hamilton said. “That adds to the case for regulation as it permits public health bodies to take more assertive action about the risks of using cannabis in adolescence and what can be done to mitigate these.”