Remember It's Natural!

 American Journal of Psychiatry (2016):

Cannabis use and DSM-IV cannabis use disorders are associated with adverse consequences (1, 2), including cognitive decline (3–5), impaired educational or occupational attainment (6–8), impaired driving ability (9–13), emergency room visits (14), psychiatric symptoms (15–17), poor quality of life (18), other drug use (19), and risk of addiction or substance use disorders (1). Despite this, Americans increasingly view marijuana use as harmless (1, 20–22) and support its legalization (23). Reflecting these changing views, 23 states now have laws permitting marijuana use for medical purposes (of which four also legalized marijuana for recreational use). Marijuana use is more prevalent in these 23 states than in others (24–26). Consistent with these changes, marked increases have occurred in the U.S. prevalence of DSM-IV cannabis use disorder among veterans (27) and adults in the general population (28, 29). Cannabis-related emergency room visits and fatal car crashes have also increased (11, 14).