They found that cannabis use among adolescents is associated with a significant increased risk of depression and suicidality in adulthood (not anxiety). While the individual-level risk was found to be modest, the widespread use of the drug by young people makes the scale of the risk much more serious.
Professor Andrea Cipriani, NIHR Research Professor of Psychiatry at the University of Oxford, said: "Our findings about depression and suicidality are very relevant for clinical practice and public health. Although the size of the negative effects of cannabis can vary between individual adolescents and it is not possible to predict the exact risk for each teenager, the widespread use of cannabis among the young generations makes it an important public health issue."
Regular use during adolescence is associated with lower achievement at school, addiction, psychosis and neuropsychological decline, increased risk of motor vehicle crashes, as well as the respiratory problems that are associated with smoking.
Professor Andrea Cipriani.