Pharmaceutical stimulant diversion, 2002–2022: data from a national sample of law enforcement and regulatory agencies in the US

Background: Nonmedical use (NMU) and diversion of stimulant medications methylphenidate and amphetamines is ongoing. Yet, data describing national diversion rates are not apparent. Methods: Data were drawn from a survey of pharmaceutical diversion completed by law enforcement. Quarterly rates of pharmaceutical stimulant diversion (per 100,000 population) were calculated for the period 2002-2022. Analyses examined changes in diversion rates following the COVID-19 pandemic. Results: There were 3,324 methylphenidate cases and 12,875 amphetamine cases reported across all 50 states. Diversion rates were characterized by an increase over time, for methylphenidate (t = 5.91, p <.0001, R² = 0.299, (Formula presented.) =.001) and amphetamines (t = 11.76, p <.0001, R² = 0.628, (Formula presented.) =.011). Beginning in 1Q2020, amphetamine diversion rates decreased by half, coinciding with the COVID-19 pandemic. Trendlines prior to 1Q2020 indicate an increase in amphetamine diversion rates over time (t = 16.89, p <.0001, R² = 0.801, (Formula presented.) =.015). Diversion rates post-1Q2020 similarly show an increase over time (t = 2.99, p =.0151, R² = 0.499, (Formula presented.) =.026). Conclusions: Findings show increases in diversion rates of pharmaceutical stimulants. Since 2020, diversion rates are on a trajectory to exceed pre-pandemic levels. Continued surveillance is warranted.