Background: Patients receiving treatment for opioid-use disorder (OUD) may experience psychological symptoms without meeting full criteria for psychiatric disorders. The impact of these symptoms on treatment outcomes is unclear.
Aims: To determine the prevalence of psychological symptoms in a cohort of individuals receiving medication-assisted treatment for OUD and explore their association with patient characteristics and outcomes in treatment.
Method: Data were collected from 2788 participants receiving ongoing treatment for OUD recruited in two Canadian prospective cohort studies. The Maudsley Addiction Profile psychological symptoms subscale was administered to all participants via face-to-face interviews. A subset of participants (n = 666) also received assessment for psychiatric disorders with the Mini International Neuropsychiatric Interview. We used linear regression analysis to explore factors associated with psychological symptom score.
Results: The mean psychological symptom score was 12.6/40 (s.d. = 9.2). Participants with psychiatric comorbidity had higher scores than those without (mean 16.8 v. 8.6, P<0.001) and 31% of those with psychiatric comorbidity reported suicidal ideation. Higher psychological symptom score was associated with female gender (B = 1.59, 95% CI 0.92-2.25, P<0.001), antidepressant prescription (B = 4.35, 95% CI 3.61-5.09, P<0.001), percentage of opioid-positive urine screens (B = 0.02, 95% CI 0.01-0.03, P<0.001), and use of non-opioid substances (B = 1.92, 95% CI 0.89-2.95, P<0.001). Marriage and employment were associated with lower psychological symptoms.
Conclusions: Psychological symptoms are associated with treatment outcomes in this population and the prevalence of suicidal ideation is an area of concern. Our findings highlight the ongoing need to optimise integrated mental health and addictions services for patients with OUD.
Keywords: Comorbidity; addiction; buprenorphine; methadone; psychiatric symptoms.