Substance use and population life expectancy in the USA: Interactions with health inequalities and implications for policy.

Life expectancy at birth for the USA has not increased in recent years. This commentary assesses the impact of substance use on this phenomenon. Although crude mortality rates of the most important causes of death (such as cardiovascular diseases or cancer) have declined between 2010 and 2014, crude mortality rates of drug- and alcohol-induced causes of death have increased. Alcohol use, non-medical prescription drug use (especially prescription opioid use) and illicit drug use have likely played a crucial role in life expectancy trends of the past years. Importantly, the current mortality crisis due to substances is disproportionately borne in lower socio-economic strata. As such, policies should reduce this impact.