Increased solitary drug use during COVID-19: An unintended consequence of social distancing.

BACKGROUND: During the COVID-19 pandemic, overdose rates substantially increased in the United States. One possible contributor to this phenomenon may be solitary drug use resulting from social distancing efforts to prevent COVID-19 transmission. METHODS: We surveyed 458 people who use drugs (PWUD) who were recruited from harm reduction and drug treatment providers located in nine states and the District of Columbia. We assessed if solitary drug use had increased since the start of COVID-19. Associations between increased solitary drug use and sociodemographic characteristics, drug use characteristics, and COVID-19 prevention behaviors were examined using multiple logistic regression. RESULTS: Half the sample identified as men (52.7%), White (49.7%), and single (49.3%). The average age was 43.2 (SD:11.8) years. Two-thirds (66.8%) recently injected drugs. 44% reported increased solitary drug use since COVID-19. Significant correlates of increased solitary drug use included being single (adjusted Odds Ratio [aOR]=1.99, 95% Confidence Interval [CI]: 1.33, 2.98), increasing drug use (aOR=2.74, 95% CI: 1.72, 4.37), using more in private locations (aOR=1.91, 95% CI: 1.34, 2.72), and social distancing behaviors (aOR=1.31, 95% CI: 1.11, 1.54). Experiencing homelessness (aOR=0.45, 95% CI: 0.31, 0.65) and identifying as a sexual minority (aOR=0.53, 95% CI: 0.31, 0.93) were associated with being less likely to increase solitary drug use. CONCLUSIONS: Solitary drug use increased during the COVID-19 pandemic. Increases in solitary drug use, in the context of a drug market increasingly permeated by fentanyl, indicates an urgent need for comprehensive harm reduction interventions to reduce overdose mortality.