Co-involvement of stimulants with opioids in North America: A 'silent epidemic’ Plos Mental Health The opioid epidemic unfolded in three distinct waves, with the latest being deaths attributed to illegally manufactured synthetic opioids. Using U.S. and Canadian data, this study reviews evidence for a 'silent epidemic' alongside the opioid epidemic that is characterized by the co-ingestion of stimulants including methamphetamine and cocaine leading to an increasing number of deaths. Trends for stimulant and opioid use were analyzed using Joinpoint regression and public interest in the substances was assessed via Google Trends. While stimulant use and its role in deaths are rising, public interest in stimulants has declined since its peak in 2004-05. Co-use leads to more deaths than either drug alone. Urgent strategies are needed to reduce harm and raise awareness among health professionals, policymakers, and the public about the dangers of stimulant-opioid co-use.   Read this issue of the ASAM Weekly Subscribe to the ASAM Weekly Visit ASAM