The potentially damaging effects of marijuana on young brains may be even worse than previously thought, according to new research conducted by scientists from McGill University. Their new study, published in Neurobiology of Disease, suggests that teenagers who consume marijuana daily face a higher risk of depression and anxiety, and may suffer irreversible neurological effects.
"We wanted to know what happens in the brains of teenagers when they use cannabis and whether they are more susceptible to its neurological effects than adults," explained McGill University researcher Gabriella Gobbi.
The study points to an apparent action of cannabis on two important compounds in the brain – serotonin and norepinephrine – which are involved in the regulation of neurological functions such as mood control and anxiety.
"Teenagers who are exposed to cannabis have decreased serotonin transmission, which leads to mood disorders, as well as increased norepinephrine transmission, which leads to greater long-term susceptibility to stress," Dr. Gobbi stated.
While previous epidemiological studies have shown how cannabis consumption can affect behavior in some teenagers, "our study is one of the first to focus on the neurobiological mechanisms at the root of this influence of cannabis on depression and anxiety in adolescents," Dr. Gobbi claimed. It is also the first study to demonstrate that cannabis consumption causes more serious damage during adolescence than adulthood.
Citation: Francis Rodriguez Bambicoa, Nhu-Tram Nguyena, Noam Katza, Gabriella Gobbi, 'Chronic exposure to cannabinoids during adolescence but not during adulthood impairs emotional behaviour and monoaminergic neurotransmission', Neurobiology of Disease, Dec. 2009; doi:10.1016/j.nbd.2009.11.020
