Cannabis users aged 16 and 17 are more than three times as vulnerable to developing an addiction to the drug than adults, researchers have found.
However, they may not be at increased risk of other mental health problems that have been linked to the drug. The findings indicate that adolescents who used cannabis were no more likely to have higher levels of subclinical depression or anxiety than adults who use cannabis.
Additionally, they were not more vulnerable than adult users to associations with psychotic-like symptoms. Lead author Dr Will Lawn said: “There is a lot of concern about how the developing teenage brain might be more vulnerable to the long-term effects of cannabis, but we did not find evidence to support this general claim. Cannabis addiction is a real issue that teenagers should be aware of, as they appear to be much more vulnerable to it than adults.
Dr Lawn, of the UCL Clinical Psychopharmacology Unit and Institute of Psychiatry, Psychology and Neuroscience at King’s College London, added: “On the other hand, the impact that cannabis use has during adolescence on cognitive performance or on depression and anxiety may be weaker than hypothesised.
“But we also replicated previous work that if someone becomes addicted to cannabis, that may increase the severity of subclinical mental health symptoms. Given adolescents are also at a greater risk of experiencing difficulties with mental health than adults, they should be proactively discouraged from regular cannabis use.”
The study involved 274 people, including 76 adolescents (aged 16 and 17) who used cannabis one to seven days per week, alongside similar numbers of adults aged 26-29. Researchers found that adolescent cannabis users were three and a half times as likely to develop severe ‘cannabis use disorder’ (addiction) than adult users.
Cannabis use disorder is defined by symptoms including cravings, cannabis use contributing to failures in school or work, heightened tolerance, withdrawal and interpersonal problems caused by or exacerbated by cannabis use. Half of the teenage cannabis users studied had six or more cannabis use disorder symptoms, qualifying as severe cannabis use disorder.
The study, published in the Journal of Psychopharmacology, found that neither teenage nor adult cannabis users were more likely to develop depressive or anxiety symptoms than non-users. A separate paper, published in Psychopharmacology, found cannabis users were no more likely to have impaired working memory or impulsivity.
However, cannabis users were more likely to have poor verbal memory – remembering things said to them.This effect was the same in adults and teenagers.
Senior author Professor Val Curran, of the UCL Clinical Psychopharmacology Unit, UCL Psychology & Language Sciences, said: “Our findings suggest that schools should be teaching pupils more about the risk of addiction to cannabis, which has been neglected in drugs education.
“Becoming addicted to cannabis is a serious problem in itself, but it can also increase the likelihood of other mental health problems. Teenagers should therefore be informed of their greater risk of addiction.”
For more stories from where you live, visit InYourArea.
