Cannabis is the most commonly used recreational drug by teenagers around the world. In England four per cent of youngsters aged between 11 and 15 have used cannabis in the last month while in Canada more than 20 per cent of 15 to 19-year-olds used cannabis over the past year.
Researchers from the University of Oxford and McGill University in Canada analysed data from 11 previous studies involving more than 23,000 people to see if using cannabis in adolescence was linked with depression. Young people who had already shown signs of depression or had a family history of depression were excluded.
They found that cannabis use by teenagers was associated with a significantly increased risk of depression and suicidal behaviour in adulthood. The individual level of risk was “modest” but the widespread use of cannabis by young people made the scale of the risk more concerning.
“We looked at the effects of cannabis because its use among young people is so common, but the long-term effects are still poorly understood,” said co-author Professor Andrea Cipriani from the University of Oxford.
“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 younger 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.”
- The full paper, Association of cannabis use in adolescence and risk of depression, anxiety and suicidality in young adulthood, was published in JAMA Psychiatry earlier this month: http://bit.ly/2IyKeM7