Inclusion criteria:
Male gender
Age ≥18 and <61 years old
Farsi speaking
Diagnosed with Methamphetamine Use Disorder (last 12 months) based on Structured Clinical Interview for DSM-5 (SCID-5)
Abstinent from any drugs except cigarettes for at least one week based on medical records or self-report, confirmed by urine analysis
Positive response to Methamphetamine cue-reactivity screening (MCS)
Willing and capable of interacting with the informed consent process8. The ability to understand, read and answer the tests
Exclusion criteria:
Unwillingness or inability to complete any of the major aspects of the study protocol, including drug cue rating, or behavioral assessment.
Abstinence from methamphetamine for more than 6 months based on self-report
Any major clinical psychiatric disorder, assessed by Structured Clinical Interview for DSM-5 (SCID-5)
Active suicidal ideation with intent or plan determined by self-report or assessment by PI or study staff during the initial screening or any other phase of the study
Positive drug test for amphetamines, opioids, cannabis confirmed by urine tests
Any active skin disorder that affects skin integrity of the scalp
Having any condition that would preclude undergoing a tDCS stimulation based on the tDCS safety checklist
Unstable medical disorder reported in subject’s medical history or by a clinician assessment
History of major head trauma, seizure, brain surgery, intracranial metal implantation
Non-correctable vision or hearing problems.