The effects of opium tincture and methadone on the cognitive function of patients with opioid use disorder

Individuals vary in their cognitive function, which is influenced by genetics and environmental factors such as opioids. Over 16 million people worldwide are affected by opioid use disorder (OUD), and opioid agonist treatment (OAT) is the most effective treatment for OUD. Evaluating cognitive function in patients with OUD receiving OAT is crucial as cognitive impairments affect everyday functioning and treatment outcomes. Studies on the cognitive effects of two forms of OAT, methadone and opium tincture (OT), have been limited and inconsistent. We thereby examined the cognitive function of patients with OUD treated with OT or methadone. In a randomized controlled trial, participants with OUD were randomized to OT or methadone. Cognition was measured by the Montreal Cognitive Assessment (MoCA). Participants completed the MoCA at baseline, week 4, 8, and 12. The cognitive function of participants improved significantly. There was improvement from OAT initiation to week 4, but this improvement plateaued from week 4 to 12. There were no significant differences in cognitive function between participants receiving OT and methadone. Our findings support the role of both OT and methadone in improving the cognitive function of patients with OUD. This may help enhance the overall rehabilitation and social reintegration of patients. •Cognition improved from opioid agonist treatment initiation to week 4 and plateaued from weeks 4 to 12.•No differences in cognition were seen between patients on opium tincture and methadone.•Both opium tincture and methadone may improve the cognition of patients with opioid use disorder.