Medications for Opioid Use Disorder Treatment, Treatment Length, and Treatment Completion Among Emerging Adults: The Moderating Role of Age and Sex

BACKGROUND: Emerging adults aged 18 to 29 with opioid use disorder (OUD) have the lowest rates of treatment engagement and retention compared to other age groups. Understanding factors that influence retention and completion in this population is critical. Given the unique developmental stage of emerging adulthood, more research is needed on the role of medications for opioid use disorders (MOUD) in improving outcomes. METHODS: = 4,126). We also explored how age and sex moderate the association between MOUD and treatment outcomes. RESULTS: Negative binomial regression showed that emerging adults of older age, female sex, White non-Hispanic race/ethnicity, higher educational attainment, and those who received the MOUD plan, without past month opioid use, and referred from institutional sources (compared to self-referral) showed longer treatment retention. Logistic regression indicated that emerging adults of male clients, individuals with higher education, those with no recent opioid use, and those referred from healthcare providers or institutional sources showed a greater likelihood of treatment completion. Moderation analyses revealed that age and sex influenced the relationship between MOUD and treatment completion: Younger emerging adults, compared to older emerging adults, and male emerging adults, compared to female emerging adults, had a lower likelihood of treatment completion when taking MOUD. In conjunction with their shorter treatment duration, this finding implies that younger emerging adults receiving MOUD may be more likely to encounter barriers to treatment completion than older adults. CONCLUSION: These findings underscore the importance of considering within-group differences among emerging adults and highlight the complex role of MOUD in treatment outcomes. Treatment strategies should be tailored to the developmental stage and demographic characteristics to improve engagement and success in OUD treatment.