Event-related Theta and Gamma Oscillations in Cue-Reactivity Test in Individuals with Opiate Use Disorder in Buprenorphine-Maintenance Program

Opioid use disorder (OUD) is a major public health problem. Maintenance treatment with medication for OUD (MOUD), such as buprenorphine, has been associated with reductions in physical symptoms of withdrawal, but attentional bias towards drug cues may contribute to the high rates of noncompliance and relapse. The cue-reactivity test can be used to investigate specifics of EEG responses to drug cues. This study was aimed at comparison of EEG oscillations during exposure to drug-related and neutral images in MOUD and control participants for investigation of attention biases persistent in MOUD. We recruited 13 MOUD outpatients and 13 age-matched controls. The cue-reactivity test used emotionally neutral and drug-related images. The study used blocked design (16 images/block, 3 s/image). Time-frequency analysis of EEG from four frontal sites was performed to assess evoked, induced, and late oscillations, and theta-gamma phase-amplitude coupling during neutral and drug blocks. Exposure to drug cues in the MOUD group resulted in increased gamma and decreased theta oscillations with higher theta-gamma coupling effect. These cue-reactivity indices reflect heightened attentional bias to drug items and vulnerability to relapse in patients on MOUD and may serve as objective treatment outcomes complementing craving reports and clinical evaluations.