Cognitive function in methadone maintenance patients compared with abstinent opioid users.

BACKGROUND Opioid is the second most prevalent illicit drug worldwide, whose consumption is very high in Iran, due to Iran's geographical proximity to producing countries. Methadone maintenance therapy is one of the most prevalent and accepted methods of substance abuse treatment. Nevertheless, cognitive disorders have been reported as one of its complications. AIM This study was conducted to evaluate cognitive impairment in methadone maintenance patients (MMPs) and to compare it with abstinent opioid users (AOUs). MATERIALS AND METHODS This cross-sectional analytical study was performed on 25 MMPs and 25 AOUs. Samples were selected through convenience sampling method whereby a self-made questionnaire was distributed among them to assess demographic information, clinical variables such as methadone and opioid use history, underlying disease and medication history, as well as 13-item Beck depression inventory. Then, they were interviewed using the Montreal Cognitive Assessment (MoCA) questionnaire. RESULTS Significant differences were found in MoCA questionnaire total scores (p = 0.018) and orientation to time and place dimension (p = 0.008) between the two groups, with the mean scores being higher in AOU group. Duration of opioid use was the only factor influencing cognitive assessment score in both Groups. (p = 0.029). CONCLUSION We suggest monitoring and assessing cognition function in patients receiving methadone especially for those with a long history of opioid use.