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.

Aims: Cognitive dysfunction plays an important role in the treatment of opioid dependence but the extent of this role and the question of whether the cognitive dysfunction is primary or secondary are matters of controversy. Few studies have been conducted in this area, particularly in abstinent opioid users. This article will give a comprehensive update of the existing literature on this issue and will also describe the protocol of a study on cognitive function in opioid dependence. Methods: The study will compare abstinent opiate-dependent patients, opiate-dependent individuals on stable maintenance treatment with no substance use and matched healthy controls. Results: We are expecting the study to provide information about the severity or possible reversal of cognitive impairment in formerly opiate-dependent patients and opiate-dependent patients on stable maintenance treatment. Conclusion: The study will answer the question of whether opioid dependence can cause impairment in cognitive and executive functions.