Neural correlates of inhibitory control in opioid use disorder: Insights from event-related potentials

Opioid use disorder (OUD) is characterized by a persistent drive to use opioids despite significant health, mental and social consequences. Better understanding of neural processes underlying inhibitory control in OUD is needed in order to effectively manage this disorder. To this end, we investigated inhibitory control function in 30 male OUD patients and 30 matched male healthy controls (HCs) by monitoring event-related potentials (ERPs) during a modified Go-NoGo task with opium-related and neutral cues. OUD patients exhibited slower reaction times and increased commission error rates compared to HCs, reflecting impaired inhibitory control. The HC group demonstrated the NoGo N2 effect known to reflect inhibitory processing; whereas no significant difference between Go and NoGo trials in the OUD group was seen. Attenuated NoGo N2 and P3 amplitudes were seen in OUD subjects, suggesting impairments in conflict resolution and late-stage inhibitory processes, respectively. Inhibitory control impairment was more pronounced as evidenced by the decreased NoGo P3 amplitudes in OUDs compared to HCs in an opium-related context. Similarly, lower Go P3 amplitudes in this context among OUDs suggest a more extensive effect on controlled processing. Finally, OUD participants showed enhanced attentional bias towards opium-related cues, as indicated by larger N1 amplitudes. Overall, these findings align with dual-process models of addiction by indicating an impaired top-down control, and increased drug cue reactivity, which likely underpins persistent addictive behaviors in OUD. The study highlights the need for therapeutic strategies focusing on inhibitory control and cue-induced craving to address OUD rehabilitation effectively.