The Role of Dose, Neurocognitive Functioning, and Psychosocial Factors on Medication Adherence in Patients Receiving Opioid Agonist Treatment

The primary aim of the present study was to examine the roles of opioid agonist treatment (OAT) medication dose, neurocognitive functioning, and psychosocial factors in predicting OAT medication adherence. We also explored the relationship between initial OAT dose requirement, a likely proxy for magnitude of prior opioid consumption, and neurocognitive functioning. Our goal was to shed light on important factors that should be targeted to improve treatment outcomes in patients entering OAT. We utilized novel, objective, and/or well-validated measures of OAT adherence (i.e., directly observed therapy), OAT dose, neurocognitive functioning, substance use, and other psychosocial factors in a sample of patients with opioid use disorder (OUD) entering OAT. Ultimately, we found that lower comorbid cocaine use and higher OAT dose level predicted better OAT medication adherence during the first 60 days of treatment. Although we found no relationship between current depressive symptomatology, social support problems, and neurocognitive functioning and OAT adherence, learning and memory and attention/working memory were worse in patients stabilized on high versus low OAT doses. The results of the present study illustrate that clinicians should target reducing polysubstance use (e.g., comorbid cocaine use) and ensuring that OAT patients are stabilized on adequately high OAT doses when entering treatment. At the same time, clinicians must recognize that patients stabilized on high OAT doses may be at risk for worse neurocognitive outcomes. Ultimately, the present study contributes to the general literature on combined factors impacting medication adherence in medical and psychiatric populations, and also addresses an important gap in the current understanding of barriers to treatment success for OUD patients