This study has two phases. In phase one (UG3), the investigators propose to use FMRI to quantify changes in brain function and EEG to examine oscillatory brain changes as well as self-reported craving before and after administration of five sessions of tDCS+Cognitive Control Network (CCN) priming stimulation vs. sham tDCS+CCN priming (randomized control trial) in 60 opioid dependent participants who recently initiated buprenorphine or methadone. Participants in the first month of prescribed buprenorphine or methadone will be assessed using FMRI and EEG, once prior to tDCS and again one week later after completion of 5 sessions of tDCS+CCN priming. With a focus on the craving outcome, the investigators will use two task-based FMRI paradigms that challenge networks associated with craving (CR) and cognitive control (CCN), and will examine these and the salience network using resting state functional connectivity. In Phase 1, FMRI and EEG will be expected to provide 1) validation of expected network and oscillatory changes from tDCS-targeting and 2) an effect size for DLPFC vs sham stimulation. Go/no go criteria for the UG3 phase will be demonstration of greater FMRI change in any node of the CR or CCN networks or enhanced frontal theta power during a WM task AND greater change (at least 10% difference between conditions, controlling for baseline craving) in subjective craving measured during a cue reactivity task or outside the FMRI following the tDCS+CCN priming intervention compared to sham tDCS+CCN priming.~In phase 2, the investigators will perform a larger RCT using the same treatment protocol in 100 opioid dependent participants who recently initiated buprenorphine or methadone. Participants will be randomized to receive five sessions of tDCS+CCN priming stimulation vs. sham tDCS+CCN priming. Phase two will address long-term (3-month) neurobehavioral outcomes, including opioid relapse, craving, and sustained fMRI changes during a paradigm that challenges networks associated with craving (CR) and cognitive control (CCN). During the 12 weeks of buprenorphine or methadone maintenance treatment, the investigators will examine our primary clinical outcome, relapse (opioid use on >4 days per month and having an opioid positive urine screen), as well as days of opioid use.
In the current proposal, the 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. Participants with opioid dependence, in the first month of prescribed buprenorphine or methadone, will be assessed twice using functional magnetic resonance imaging (FMRI) and electroencephalographic (EEG), once prior to tDCS+CCN priming and again at the completion of 5 sessions of tDCS+CCN priming (one week later). Task-based and resting state functional connectivity will be used to examine networks associated with craving (CR) and cognitive control. In Phase 1, FMRI and EEG will provide validation of expected changes in these networks following tDCS stimulation of the DLPFC. In phase 2, the investigators will perform a larger randomized clinical trial (RCT) (vs. sham control) to address long-term neurobehavioral outcomes, including opioid relapse, craving, and sustained FMRI changes.