Polysubstance Use by Stimulant Users: Health Outcomes Over Three Years

OBJECTIVE: Studies show that stimulant users have varied substance use patterns and that polysubstance use is associated with poorer past or concurrent medical, mental health, and substance use outcomes. This study examined outcomes of substance use patterns prospectively. METHOD: A latent class analysis was conducted to examine substance use patterns among adults using stimulants (n = 710; 38.6% women) at baseline, and the health and treatment utilization outcomes of different use patterns over the subsequent 3 years. To examine associations between latent class membership and outcomes, generalized estimating equation modeling was conducted. RESULTS: Four classes of substance use patterns at baseline were identified, involving high use of (a) methamphetamine and marijuana (23%); (b) crack cocaine and alcohol (25%); (c) powder cocaine, alcohol, and marijuana (23%); and (d) nonprescribed opioids, alcohol, marijuana, crack cocaine, and powder cocaine (i.e., polysubstance [29%]). Polysubstance class members had poorer physical health and mental health status, and more severe substance use, over the subsequent 3-year period, than other class members. Regarding treatment utilization, polysubstance class members had more medical care utilization than crack cocaine class members, and more substance use treatment utilization than powder cocaine class members. The methamphetamine, crack cocaine, and powder cocaine classes did not differ from each other on any health or treatment utilization outcome. CONCLUSIONS: People using stimulants commonly use other substances, and those whose polysubstance use includes nonprescribed opioids have especially poor health outcomes.