Background: Levels of mental distress are high in patients with substance use disorders (SUD) and investigation of correlates may broaden our understanding of this comorbidity.
Objectives: We investigated self-reported symptoms of mental distress among individuals entering either outpatient opioid maintenance treatment (OMT) or other inpatient SUD treatment and related factors, with a particular focus on perceived self-control.
Methods: A cross-sectional study including substance users (n = 548; mean age 34 years; 27% women) entering treatment at 21 different treatment-centers across Norway, interviewed between December 2012 and April 2015. Symptoms of mental distress were assessed with Global Symptom Index (GSI) score. Adjusted relative risk ratios (RRR) with 95% confidence intervals (CI) were estimated through multinomial logistic regression.
Results: More than half of the participants in both treatment groups reported mental distress (GSI) above clinical cut-off. The use of alcohol and exposure to violence were associated with increased likelihood of high GSI for both patient groups. Also, lower perceived self-control was related to high GSI in both treatment groups.
Conclusion: Symptoms of mental distress were equally common among patients entering OMT and those entering other inpatient SUD treatment, even if the patients differed on a number of clinical characteristics. Use of alcohol and exposure to violence were associated with more mental distress in both groups. Perceived self-control also appeared to be important when explaining symptoms of mental distress among these SUD patients.
Keywords: Co-occurring disorders; depressive symptoms; opioid maintenance treatment; self-control; substance use treatment.