Zapping the brain to make better choices: a new hope for opioid addiction?

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

* INCLUSION CRITERIA: In order to be eligible to participate in this study, an individual must meet all of the following criteria: Both groups: -Participants will be volunteers between the ages of 18-60. Opioid-using group: * Participants must meet DSM-5 criteria for an opioid use disorder (active or in remission and on maintenance therapy). * Participants must be currently enrolled in and receiving medication-assisted treatment for opioid use disorder (MOUD; such as methadone, buprenorphine or naltrexone) and report a stable dose of their medication for at least 4 weeks prior to enrollment.\* * Participants in this group can meet DSM-5 criteria for other substance use disorders (such as alcohol, nicotine, or cocaine use disorder) currently or in the past but must also meet criteria for an OUD. * To note, participants in the opioid-using group will not receive direct clinical care from NIDA study staff, but enrollment in a MOUD program will be required for inclusion in this study. This will be assessed by self-report of enrollment in a known MOUD program and a urine screen confirming their reported treatment. Participants will also sign a release of information (ROI) form that provides contact details for their treatment provider and allows for communication between the study team and the participants treatment provider if necessary. EXCLUSION CRITERIA: An individual who meets any of the following criteria will be excluded from participation in this study: Controls: -Participants cannot meet DSM-5 criteria for current substance use disorders other than nicotine and marijuana and cannot meet criteria for current moderate or severe alcohol use disorder. All participants: * Participants cannot meet DSM-5 criteria for lifetime and/or current psychotic disorders such as bipolar disorder, schizophrenia, schizoaffective disorder. * Participants cannot have a history of major head trauma resulting in cognitive impairment, seizure, or other neurological disorders. * Participants cannot have any history of significant neurological disorders, including seizures, epilepsy, or cognitive impairment which may impact MRI metrics. MAI will use discretion in evaluating the impact of minor events or history reported. * Participants cannot be pregnant. * Participants with Major Depressive Disorder (per DSM-V criteria) must be stable on medication(s) for 3 months. * Subjects with suicidal ideation where outpatient treatment is determined unsafe. * Subjects that cannot speak English. Justification: To include non-English speakers, we would have to translate the consent and other study documents and hire and train bilingual staff, which would require resources that we do not have and could not justify, given the small sample size for each experiment. Additionally, the data integrity of some of the cognitive tasks and standardized questionnaires used in this study would be compromised as they have only been validated in English. Most importantly, ongoing communication regarding safety procedures is necessary when participants are undergoing MRI procedures. The inability to effectively communicate MRI safety procedures in a language other than English could compromise the safety of non-English speaking participants. * Any contraindications to MRI. * For subjects continuing to the TMS portion of the protocol, contraindications for TMS.