Cannabis and psychosis: what is the link?
Journal of psychoactive drugs June 1, 2007 Mohamed Ben Amar, Stéphane Potvin
Cannabis consumption appears to increase the risk of psychotic symptoms, but whether it causes psychosis remains uncertain. A review of ten epidemiological studies found that three supported a causal link between cannabis use and diagnosed psychosis, five suggested chronic use increases psychotic symptoms without leading to diagnosed psychosis, and two found no causal relationship. Heavy consumption, prolonged use, early exposure, and underlying psychotic vulnerability may contribute. Potential neurobiological mechanisms involve dopamine, endocannabinoids, and brain growth factors. Uncertainty persists due to challenges in measuring cannabis use and psychosis, possible reverse causality, and residual confounding factors.