Sociodemographic and patient reported outcomes by racial and ethnicity status among participants in a randomized controlled trial for methamphetamine use disorder

Background There has been a significant increase in methamphetamine use and methamphetamine use disorder (Meth UD) in the United States, with evolving racial and ethnic differences. Objectives This secondary analysis explored racial and ethnic differences in baseline sociodemographic and clinical characteristics as well as treatment effects on a measure of substance use recovery, depression symptoms, and methamphetamine craving among participants in a pharmacotherapy trial for Meth UD. Methods The ADAPT-2 trial (ClinicalTrials.gov number, NCT03078075; N=403; 69% male) was a multisite, 12-week randomized, double-blind, trial that employed a two-stage sequential parallel design to evaluate the efficacy of combination naltrexone (NTX) and oral bupropion (BUP) vs. placebo for Meth UD. Treatment effect was calculated as the weighted mean change in outcomes in the NTX-BUP minus placebo group across the two stages of treatment. Results Of the 403 participants in the ADAPT-2 trial, the majority (65%) reported non-Hispanic White, while 14%, 11% and 10% reported Hispanic, non-Hispanic Black, and non-Hispanic other racial and ethnic categories respectively. At baseline non-Hispanic Black participants reported less severe indicators of methamphetamine use than non-Hispanic White. Treatment effects for recovery, depression symptoms and methamphetamine cravings did not significantly differ by race and ethnicity. Conclusions Although we found racial and ethnic differences at baseline, our findings did not show racial and ethnic differences in treatment effects of NTX-BUP on recovery, depression symptoms and methamphetamine cravings. However, our findings also highlight the need to expand representation of racial and ethnic minority groups in future trials.