tDCS and Urge in BFRBs

Inclusion Criteria: * Ability to provide informed consent (as established by clinical interview), and voluntary, signed informed consent prior to the performance of any study specific * Ability and willingness to perform study-relevant clinical assessments and tDCS * Endorses mild to extreme intensity of urges to pick or bite their skin or nails Exclusion Criteria: * Any unstable medical, psychiatric, or neurological condition (including active or otherwise problematic suicidality) that may necessitate urgent treatment * Daily use of psychotropic medications that substantially lower seizure threshold (e.g., clozapine) * History of psychosis, mania, major neurological disorder, significant head trauma, or seizures/epilepsy * Current suicidal intent * Any major neurological disease or history of major head trauma, including concussion with extended loss of consciousness, or of psychosurgery * Current or suspected pregnancy * Endorsing possible contraindications for tDCS