Open-label Feasibility Trial of HD-tDCS During Cognitive Behavioral Therapy for Cocaine Use Disorder

Among persons with SUD, those with low CF show more attentional bias toward reward-associated cues, where relapse may stem from reward circuit activation by drug cues that is insufficiently checked by the neurocircuitry of the dorsolateral prefrontal cortex (DLPFC) thought to regulate behavior. Many skills for SUD recovery taught in cognitive behavioral therapy (CBT) are reliant on DLPFC directed top-down regulation, such as recognizing environmental triggers and recalling more healthy coping strategies. However, a challenge for CBT is poor encoding, retention and in situ invocation of these skills. Of interest is improving brain function in these individuals to assist in CBT effectiveness. One option is to use stimulants which have been shown to reduce cocaine use, but they have abuse potential. It is thus critical to discover safer neurobiological interventions that could improve CBT success without risking problematic interactions with commonly prescribed psychotropic medications.

A promising neurobiological intervention for CocUD is transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique that induces changes in neuronal excitability via hypo- or hyper-polarization of underlying resting membrane potentials, resulting in lasting changes in network connectivity that extend beyond the stimulated brain region. When applied over DLPFC, tDCS has been shown to increase memory recall and other CF in older adults with mild cognitive impairment. In SUD, tDCS has also reduced stimulant craving compared to sham stimulation and to reduce rates of relapse in crack cocaine users. In persons with methamphetamine use disorder, tDCS over DLPFC reduced cue-induced drug craving, and this reduction correlated with tDCS-reinforced functional connectivity in the executive control brain network. Thus, tDCS may improve CBT encoding and adherence without potential side effects and abuse potential of medications.

Inclusion criteria

• Between 18 and 65 years-of-age.
• Meet current DSM-5 criteria for Cocaine Use Disorder (CocUD), moderate or severe
• Professed interest in CocUD treatment or reducing cocaine use.
• Understand and comply with study procedures
• Positive urine result for cocaine metabolite in at least one screening visit.

Exclusion criteria

• Current DSM-5 diagnosis of any non-cocaine substance use disorder (SUD) other than alcohol use disorder-mild or cannabis use disorder-mild
• Epilepsy or a history of multiple seizures
• Taking any medications known to reduce seizure threshold
• History of migraines, ringing in the ears, and/or a head injury that resulted in a diagnosis of concussion and/or loss of consciousness
• Current scalp condition (e.g. psoriasis) or head wound that has not completely healed
• Currently pregnant or hoping to become pregnant at any point during the study
• Significant current suicidal or homicidal ideation
• Metal plate in skull or other embedded metal fragments in body or other bodily metal
• Claustrophobia or other MRI contraindications
• Fitted with electrical implants such as pacemaker
• Present with clinically significant symptoms of acute cocaine or opioid withdrawal (these individuals would be rescheduled after resolution of acute withdrawal, if possible).