Abstract
BACKGROUND: Limited literature exists on how concurrent substance use and difficulty meeting basic needs impact recent psychiatric treatment among people who inject drugs (PWID) with diagnosed mental health disorders in the U.S. This study assessed the prevalence of taking current psychiatric medication treatment, and its association with concurrent substance use and subsistence difficulty. METHOD: Baseline data from a prospective cohort study in Los Angeles, CA and Denver, CO between April 2021 and November 2022 were analyzed. Modified Poisson regression assessed the association between demographics, concurrent substance use, subsistence difficulty, and recent psychiatric medication treatment. RESULTS: Out of 429 PWID, 287 (66.9%) who reported a history of diagnosed mental health disorders were included. Among them, 86.8% of participants were unhoused or unstably housed, and 22.6% reported taking prescribed psychiatric medications in the past three months. Factors positively associated with current psychiatric medication treatment included older age (40-59: adjusted prevalence ratio [aPR] = 1.84, 95%CI: 1.15, 2.94); 60-76: aPR = 2.22, 95%CI: 1.21, 4.06; vs. 20-39 years old), non-medical prescription opioid use (aPR = 1.57, 95%CI: 1.06, 2.35), and recent overdose (aPR = 2.16, 95%CI: 1.45, 3.22). Conversely, being unhoused or unstably housed (aPR = 0.51, 95%CI: 0.29, 0.89) and high subsistence difficulty (aPR = 0.41, 95%CI: 0.21, 0.81) were less likely to take prescribed psychiatric medications. CONCLUSION: A significant gap exists in psychiatric medication treatment among PWID with diagnosed mental health disorders. Integrated treatment programs addressing essential needs, such as food and clothing, alongside overdose prevention and mental health care, are urgently needed, particularly for those struggling with substance use and housing instability.