Good News For The Medical Marijuana Movement: pot Proliferates Brain Cells And Boosts Mood: "Most drugs of abuse decrease the generation of new neurons in the brain, but the effects of marijuana on this process, called neurogenesis, had not been clear. In a paper appearing online on October 13 in advance of print publication of the November issue of the Journal of Clinical Investigation, Xia Zhang and colleagues from University of Saskatchewan show that a potent and synthetic cannabinoid promotes neurogenesis. This drug also exerts anti-anxiety and antidepressant-like effects. "