The continued rise of methamphetamine use among people who use heroin in the United States

Background: Methamphetamine use is a growing public health concern in the United States. Prior analyses with nationally representative data from 2015 to 2017 suggested that increases in methamphetamine use appeared largely selective to people using heroin. This analysis updated prior estimates to determine if trends are selectively persistent and how they compare to historical trends. We also evaluate sociodemographic risk factors associated with methamphetamine use among people using heroin. Methods: Data from the 2015–2019 National Surveys on Drug Use and Health (NSDUH) were analyzed. Data from the 2006–2014 NSDUH were summarized for historical trends. Past month and past year methamphetamine use prevalence was determined within populations using heroin as well as those using other drugs (e.g., cocaine, cannabis). Multivariable logistic models accounting for complex survey design evaluated predictors of methamphetamine use among people using heroin. Results: From 2015 to 2019, past month methamphetamine use increased from 9.0% to 44.0% within the population of people reporting past month heroin use. Similarly, past year methamphetamine use increased from 22.5% to 46.7% among those reporting past year heroin use. Risk factors for methamphetamine use among people using heroin included rurality, past year injection drug use, and serious mental illness. Conclusions: A rapid, selective, and sustained increase in methamphetamine use is evident among people using heroin. These findings combined with similar findings in treatment admission and overdose data emphasize the need for increased attention to a specific type of high-risk use pattern in the United States, an issue that appears increasingly unlikely to naturally resolve.