Though behavioral interventions and medications have shown efficacy for individuals suffering from an opioid use disorder (OUD), there is a substantial sub-population that does not respond to currently available treatments. Through a secondary data analysis, this study finds evidence for the existence of treatment-resistant opioid use disorder (TROUD) by determining and examining factors associated with low and high treatment groups. This study provides evidence that failure to successfully complete treatment is related to the disorder's resistance, thereby opening new clinical and research paths that can help in designing personalized therapies to treat TROUD. [ABSTRACT FROM AUTHOR]