There are multiple explanations for decreased mortality with cannabis use; however, this remains unknown. First, it is possible that cannabis users may have higher functioning and in return may have lower mortality. We did not find differences however in GAF scores, however this may not adequately proxy symptomatology and functioning. Also, cannabis itself may have some health benefits. The psychoactive component of cannabis, d9-tetrahydrocannabinol, is well tolerated and already in clinical use for nausea associated with cancer chemotherapy and appetite stimulation with the AIDS wasting syndrome. In the cannabis users group there were no deaths from cancer during the follow up period while there were four cancer deaths in the cannabis non-users group. Activation of microglial CB1 has been shown to inhibit the release of nitric oxide, suggesting that CB1 may be anti-inflammatory (Waksman et al., 1999). In addition, the endocannabinoid system has been shown to attenuate inflammatory events such as the differentiation of myelin-specific T cells, the production of pro-inflammatory mediators (tumor necrosis factor (TNF)-α, nitric oxide (NO), interleukin (IL)-1β, IL-2 and IL-6 and the activation and infiltration of
