Mindfulness meets nerve zapping: a new way to curb heavy drinking?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Currently living in Massachusetts. * Aged 21-29 years old. * Consume either more than 14 standard drinks of alcohol per week OR at least 5 standard drinks in one day per week (in past 30 days). * Have sufficient English fluency to understand procedures and questionnaires. * Have the capacity and ability to provide informed consent. * Scores at least 15 points on the PACS at screening. Participants who score between 10 and 14 pts will undergo additional doctoral-level review to assess eligibility. Exclusion Criteria: * Current or past diagnosis of a substance use disorder based on the Quick Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) Module C (Substance Use Disorders). * Active prescription for sedative/hypnotics, opioids, or anesthetic medications. * Active prescription for medications used to treat alcohol use disorder (AUD), e.g., naltrexone, disulfiram, acamprosate, etc. * Active psychosis or schizophrenia-spectrum disorder diagnosis. * Bipolar I disorder history or severe level of mania. * Severe symptoms of PTSD. * Acute suicidality or self-injurious behavior. * Cognitive inability as demonstrated by the inability to complete an informed consent assessment with \>90% accuracy after 2 attempts. * Current participation in another experimental intervention research study. * Current daily mindfulness practice \>10 minutes per day. * Participation in an 8-week intensive Mindfulness-Based Intervention or residential meditation retreat in past 3 years. * Expected medical hospitalization in the next 2 months; or are currently pregnant. * Expected incarceration in the next 2 months. * Presence of electronic implants, such as heart pacemakers, defibrillators, or pumps. * Presence of a cardiac rhythm disorder. * History of seizures. * Presence of skin disorders or malignant diseases in the area in or around the left ear. * Lack of alcohol craving as assessed by the PACS during screening (score of \< 10 points).