Interrelationship of Opioid Dependence, Impaired Impulse Control, and Depressive Symptoms: An Open-Label Cross-Sectional Study of Patients in Maintenance Therapy.

OBJECTIVE: A growing number of studies indicate increased impulsivity in patients with opioid dependence (OD). However, few studies exclude concomitant drug use and consider depression as a comorbidity, both of which can bias results.

AIM: We aimed to compare impulsivity in patients with OD enrolled in maintenance therapy (ICD code F11.22) and well-matched healthy controls taking psychopathological impairments into account. Furthermore, we compared the result to risky behavioral patterns in patients.

METHODS: This cross-sectional study included 50 patients with OD enrolled in either methadone or buprenorphine maintenance therapy and 50 healthy controls matched for gender, age, education, marital status, and premorbid intelligence. Abstinence from benzodiazepines, amphetamines, and cocaine was verified by urine analysis. We used the Barratt Impulsiveness Scale 11 (BIS-11), Beck's Depression Inventory (BDI), the Symptom Checklist 90 Revised (SCL-90R), and the European version of the Addiction Severity Index (EuropASI).

RESULTS: Patients exhibited significantly worse impulse control than healthy individuals. We found no correlation between impulsiveness and reported risky behavior patterns but found a significant correlation between depressive symptoms and psychopathological impairment.

CONCLUSIONS: Patients with OD showed a higher impulsivity than healthy individuals. Impulsivity could be a cause or a consequence of a substance use disorder; further research is warranted to explain this relationship. Impulsivity was associated with depression, an important confounder; future research needs to take this into account.