Characterization Imaging Instruments in Alcoholics and Non-Alcoholics

* INCLUSION CRITERIA: All adult participants must be: * Age 18 years or older, * Have been pre-screened, determined eligible for any NIAAA study, or enrolled in any NIAAA study (including 14-AA-0181). EXCLUSION CRITERIA: As this is a natural history protocol, there are no exclusionary criteria for this study. Participants should have been tested negative prior to the time of consent and study procedures using an alcohol breathalyzer, urine drug (UDT) and, when applicable, pregnancy tests. Individuals with a positive breath alcohol concentration (BrAC), UDT, or pregnancy test will be re-scheduled or withdrawn from the study. Upon completion of the consent, the participant will be invited for the study session. On the study session day, the following exclusion criteria will be applied. -Exclusion criteria for MR scan\* * Positive BrAC#, * Positive urine drug test (UDT) # for benzodiazepines, cocaine, methamphetamines, and opiates for outpatients. Positive UDT for benzodiazepines is not exclusionary for the inpatients. It is common that the inpatients who are treated for AUD withdrawal are treated with benzodiazepines. Positive THC would also not be exclusionary for this study since it tends to be detected over the long period of time after use. However, we will make note of these for the data analysis purposes. * Task performance (behavioral, fMRI) only: cleared based on neuromotor examination, * Presence of ferromagnetic objects in the body that are contraindicated for MRI of the head (pacemakers or other implanted electrical devices, brain stimulators, some types of dental implants, aneurysm clips, metallic prostheses, permanent eyeliner, implanted delivery pump, or shrapnel fragments), * Cannot lie comfortably flat on back for up to 2 hours in the MRI scanner, * Uncomfortable in enclosed spaces (has claustrophobia) such that they would feel discomfort in the scanner, * Women: are pregnant#, * Are left-handed. * Inpatient participants with alcohol use disorder who have symptoms of alcohol withdrawal as indicated by the most recent measurement within the past 30 days, measured by the Clinical Institute Withdrawal Assessment (CIWA-Ar) score \> 8. * Subjects excluded from MR scan may still perform the behavioral tasks which would otherwise be performed in the scanner, if they qualify for behavioral tasks. To avoid undue discomfort, burden, and inconvenience this information, if available, can be gathered from routine clinical care or other NIAAA clinical studies and data. * Participants who meet this exclusion criterion will not participate in any part of this study at the time. They will be re-scheduled for a future date(s) when they do not meet any of the exclusionary criterion.