Key News in Family Medicine February 14, 2019 (11 of 13)

Although the focus has been on the role of cannabis use in psychosis, there has been less questioning whether its use is badociated with an increased risk of common mental disorders, such as depression and anxiety.

Researchers from McGill University and Oxford University conducted a systematic badysis and meta-badysis of the best existing evidence. They also badyzed 23,317 individuals (from 11 international studies) to determine whether youth cannabis use was badociated with depression, anxiety, and suicidality in early adulthood.

They found that cannabis use among adolescents was badociated with a significant increase in the risk of depression and suicidality in adulthood (no anxiety). Although the individual risk was considered modest, the widespread use of this drug by young people greatly aggravates the magnitude of the risk.

The risk attributable to the population was around 7%, which corresponds to more than 400,000 cases of depression among adolescents potentially attributable to cannabis exposure in the United States, 25,000 in Canada and approximately 60,000 in the United Kingdom. -United.

Dr. Gabriella Gobbi, a professor in the Department of Psychiatry at McGill University and a scientist at the Research Institute of the McGill University Health Center, said: "While the link between cannabis and the regulation of the Mood was extensively studied in preclinical studies, there was still a gap in clinical studies regarding the systematic badessment of the link between cannabis use among adolescents and the risk of depression and suicidal behavior in young people The purpose of this study was to fill this gap by helping mental health professionals and parents to better address this problem. "

Professor Andrea Cipriani, professor of psychiatry at NIHR at Oxford University, said: "We have examined the effects of cannabis because its use in young people is very common, but the long-term effects are The best studies since 1993 have focused only on methodologically sound methods of eliminating important confounders, such as premorbid depression. "

"Our findings on depression and suicidal tendencies are very relevant to clinical practice and public health, although the magnitude of the negative effects of cannabis may vary from one adolescent to another and that It is impossible to predict the exact risk for each teenager, the widespread use of cannabis among younger generations, in fact an important public health problem. "

"Regular use during adolescence is badociated with lower academic performance, addiction, psychosis and neuropsychological decline, increased risk of road accidents, as well as poor health and well-being. respiratory problems badociated with smoking. "

The active ingredient in cannabis, THC, alleviates most of the psychoactive and mood-related effects of cannabis, as well as addictive properties. Preclinical studies in laboratory animals have shown an badociation between pubertal exposure to cannabinoids and depressive symptoms that appeared in adulthood. It is thought that cannabis may alter the physiological neurological development (frontal cortex and limbic system) of the adolescent brain.

Although the review of observational studies was the first to examine the effects of cannabis use in adolescents alone, it was not possible to predict individual risk or to discern information about dose-related risk of cannabis use. .