To legalize or not to legalize? - analysis of association between cannabis use and psychosis frequency and clinical manifestation

The association between cannabis use and psychotic disorders has long been recognized. Among others, it is evidenced that cannabinoids can produce transient positive, negative and cognitive psychotic symptoms in healthy individuals and exacerbate symptoms and trigger relapse on the course of established psychotic disorder. But until recently, little was known about the mechanism, by which these effects are caused. According to the newest research, the mechanism may involve dopamine, GABA or glutamate neurotransmission. As only a small proportion of total population exposed to cannabinoids develops psychotic disorders, it is likely that cannabinoids are not the main causative factor of psychosis but may play a role of significant risk factor that contributes to psychosis manifestation. Such parameters as dose, duration and the age of first exposure to cannabinoids are well established modifying factors of psychosis course, however the mechanisms of this association are still mostly unknown. Recently, more and more attention has been given to the novel hypotheses including the role of cannabinoids on neurodevelopment of central nervous system. It is proved that endocannabinoids may play an important role in such processes as neurogenesis, neural specification, neural maturation, neuronal migration, axonal elongation, and glia formation. Use of exogenous cannabinoids, by disrupting the endocannabinoid system and interfering with neurodevelopmental processes, may provide a mechanism by which exposure to cannabinoids during adolescence may.