Narrative minireview of the spatial epidemiology of substance use disorder in the United States: Who is at risk and where?

Abstract

Drug overdose is the leading cause of death by injury in the United States. The incidence of substance use disorder (SUD) in the United States has increased steadily over the past two decades, becoming a major public health problem for the country. The drivers of the SUD epidemic in the United States have changed over time, characterized by an initial heroin outbreak between 1970 and 1999, followed by a painkiller outbreak, and finally by an ongoing synthetic opioid outbreak. The nature and sources of these abused substances reveal striking differences in the socioeconomic and behavioral factors that shape the drug epidemic. Moreover, the geospatial distribution of the SUD epidemic is not homogeneous. The United States has specific locations where vulnerable communities at high risk of SUD are concentrated, reaffirming the multifactorial socioeconomic nature of this epidemic. A better understanding of the SUD epidemic under a spatial epidemiology framework is necessary to determine the factors that have shaped its spread and how these patterns can be used to predict new outbreaks and create effective mitigation policies. This narrative minireview summarizes the current records of the spatial distribution of the SUD epidemic in the United States across different periods, revealing some spatiotemporal patterns that have preceded the occurrence of outbreaks. By analyzing the epidemic of SUD-related deaths, we also describe the epidemic behavior in areas with high incidence of cases. Finally, we describe public health interventions that can be effective for demographic groups, and we discuss future challenges in the study and control of the SUD epidemic in the country.

Keywords: Substance use disorder; Spatial epidemiology; Risk factors; Spatial statistics; Disease mapping

Core Tip: A comprehensive geographical analysis of the substance use disorder (SUD) epidemic is fundamental to understanding the dynamics of the epidemic and to identifying important factors associated with the spatial dynamics of the disease. The SUD epidemic is not uniformly distributed within the United States. The epidemic is characterized by the emergence of several micro-epidemics of different intensities across demographic groups and geographical locations across the country. Micro-targeting strategies based on understanding the spatial structure and the multifactorial nature of the addiction epidemic would facilitate the design of integrated preventive strategies for substance use in vulnerable populations in the United States.