If the legalization of marijuana for medical purposes truly leads to reductions in suicide rates, this would have important implications for public health and policy. Suicide is among the ten leading causes of death in the United States and the 4th leading contributor to years of potential life lost among people under 65 (Centers for Disease Control and Prevention, 2014; Murphy et al., 2013). Any true effect on suicide rates should be seriously considered in the policy debates surrounding both medical and recreational marijuana. However, a protective effect against suicide is surprising given that neurodevelopmental and psychiatric effects—including suicide risk—are among the primary health concerns associated with regular marijuana use (Batalla et al., 2013; Hall and Degenhardt, 2009; Meier et al., 2012; Moore et al., 2007; Price et al., 2009; van Ours et al., 2013; Volkow et al., 2014). Given the relevance of such a finding to policy, the suggestion that medical marijuana policies might lead to lower rates of suicide warrants closer scrutiny.
