RS-tDCS for Cannabis Use Disorder: The C.A.R.E.S. Initiative

The purpose of this sham-controlled pilot randomized controlled trial (RCT) is to evaluate the feasibility, safety, and preliminary efficacy of a one-month intervention consisting of 20 home-based active or sham RS-tDCS sessions paired with audio track guided mindfulness meditation practice in otherwise healthy adults seeking to reduce cannabis use in the context of cannabis use disorder (CUD).

Inclusion Criteria: 1. Aged 22-65 years (inclusive) 2. Currently meets the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) criteria for CUD, as determined by DSM-V criteria (M.I.N.I) 3. Positive for cannabis on the 11-COOH-THC single panel urine test 4. Seeking treatment to reduce or discontinue cannabis use (Marijuana Ladder ranged between 5-8 \[inclusive\]) 5. Kessler Psychological Distress Scale (K10) score \< 35 (minimal to moderate distress) 6. Wide Range Achievement Test-5(WRAT-5) score ≥ 85 7. Ability to use mobile devices 8. Fluent in English or Spanish Exclusion Criteria: 1. Cannabis is used exclusively as prescribed or directed by their provider 2. Meets DSM-V criteria for substance use disorder within the past six months for any psychoactive substance other than cannabis 3. Meets DSM-V criteria for alcohol use disorder within the past six months 4. Primary psychiatric disorder (major depressive disorder, bipolar disorder, or psychotic disorder) as the principal diagnosis, independent of cannabis use disorder; or current diagnosis of bipolar disorder, psychotic disorder, or any other alcohol/substance use disorder as defined by DSM-5-TR and confirmed via the Mini-International Neuropsychiatric Interview (MINI). 5. Primary neurologic or major medical disorder that would interfere with study participation. 6. Enrolled in group or individual therapy for substance use disorder that would be concurrent with the study intervention 7. History of moderate or severe traumatic brain injury 8. Seizure disorder or recent (\<5 years) seizure history 9. Presence of metal or active implants in the head/neck 10. Any skin disorder or skin sensitive area near stimulation locations 11. Pregnant or planning pregnancy during the study period or breastfeeding