Causes and Consequences of Illicit Drug Epidemics

Large and rapid upswings in illicit drug use display similar properties to infectious disease epidemics. In this chapter, we review research to understand what causes drug epidemics and how they end. Drug market actors are subject to both positive and negative reinforcement that lead to rapid, nonlinear increases and decreases in drug market activity. There is evidence that drug epidemics cause serious problems, including drug overdoses, adverse birth outcomes, homicides, lower educational attainment, and migration from neighborhoods subject to intense drug market activity. Many of these costs are borne by those who do not consume or sell drugs. Given the frequency, size, and impacts of illicit drug epidemics, they deserve more attention by researchers and policy-makers.