Effects of teen marijuana use persist in adulthood 12/24/09 | Top News | Anjali Singh In teens use of marijuana may bring about neurological changes in the developing brain. These changes in adulthood leads to increased anxiety and stress levels, new animal research suggests. The study, by Dr Gabriella Gobbi, a psychiatric researcher from the Research Institute of the McGill University Health Centre in Montreal, suggests that daily cannabis consumption can lead to depression and anxiety. Gobbi after a study stated, "We found after working with the animals that when those that were exposed to cannabis as adolescents became adults they had low serotonin activity, which is related to depressive behavior, and high norepinephrine levels, which is related to an increase in anxiety and stress.” The results of the study were published online on December 5 in advance of publication in an upcoming print issue of Neurobiology of Disease. It was also reported that marijuana’s main ingredient, delta 9, tetrahydrocannabinol (THC), was previously believed to have an impact on receptors in the brain that regulate cognition and emotion.