RecruitingDevice studytDCS to Decrease Opioid Relapse (UH3)Investigators will measure behavioral and brain responses following transcranial direct current stimulation (tDCS) to the dorsolateral prefrontal cortex (DLPFC) (anode on right DLPFC, cathode on the left DLPFC) delivered during cognitive control network (CCN) priming. In Phase I, the EEG provided validation of expected changes in these networks following tDCS stimulation of the DLPFC. In this current phase (II), the investigators will perform a larger randomized clinical trial (RCT) (active vs. sham control) to address long-term neurobehavioral outcomes, including opioid relapse, craving, and sustained EEG changes.