Pot damage on teens worse than thought

MONTREAL, Dec. 23 (UPI) -- Daily consumption of marijuana in teens can cause depression and anxiety, and have an irreversible long-term effect on the brain, Canadian researchers say.

Dr. Gabriella Gobbi, a psychiatric researcher at the Research Institute of the McGill University Health Centre in Montreal, says the damaging effects of marijuana on young brains are worse than originally thought.

"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," Gobbi says in a statement.

"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."

Previous epidemiological studies have shown how cannabis consumption can affect behavior in some teenagers, Gobbi says.

The study, published in Neurobiology of Disease, also demonstrates that marijuana consumption causes more serious damage during adolescence than adulthood.