Inclusion Criteria:  Inclusion criteria for both study groups (AUD and controls)  Age 21 years to 65 years old. Willingness to provide signed, informed consent and commit to completing the procedures in the study Participants must be informed of the investigational nature of this study and provide written informed consent in accordance with institutional and federal guidelines prior to study-specific procedures.  Participants must agree to not consume alcohol beverages for 24 hours prior to each laboratory session.  Inclusion criteria for the AUD group:  Meets DSM-5 criteria for current AUD Participants report average weekly ethanol consumption of at least 15 standard drinks weekly over the past month prior to consent (self-report) Minimum 1 year history of heavy drinking (self-report). Must have had last drink within 1 week of PET visits. Participants not seeking treatment for their AUD (self-report)  Alcohol specified as the preferred drug (self-report).  Inclusion criteria for the control group:  AUDIT score < 6  Fewer than 5 standard drinks per month  Exclus1. Females who are pregnant or breast-feeding will not be eligible for this study. Female participants of child-bearing potential will have a urine pregnancy test prior to FDG injection.  2. Unwilling or unable to refrain from use, within 24 hours of FDG PET/CT scan procedures, psychoactive medications or medication that may affect study results (e.g., analgesics containing narcotics, antibiotics, anti-inflammatory drugs).  3. Current DSM-5 diagnosis of a major psychiatric disorder (other than nicotine use disorders, or marijuana use disorders that are mild/moderate in both groups; and alcohol in the AUD group) that required hospitalization, or that required daily medications for over 4 weeks in the past year (i.e., antidepressants; anticholinergics; antipsychotics; anxiolytics; lithium; psychotropic drugs not otherwise specified (nos) including herbal products (no drugs with psychomotor effects or with anxiolytics, stimulant, antipsychotic, or sedative properties); sedatives/hypnotics).  4. Positive urine drug screen positive for any substances, other than marijuana, on study visits (may be repeated once and if the result is negative on repeat it is not exclusionary).  5. Serious or unstable medical or psychological conditions that, in the opinion of the investigator would compromise the subject's safety or successful participation in the study.  6. Currently suffering from or with a history of stroke and/or stroke related spasticity per medical record review or self report.  7. History of seizures per medical record review or self report. 8. HIV positive, as the human immunodeficiency virus may affect the brain, per medical record review or self report or by testing at screening.  9. Head trauma with loss of consciousness for more than 30 minutes or associated with skull fracture or inter-cranial bleeding or abnormal MRI. (self-report, medical record review).  10. Presence of ferromagnetic objects in the body that are contraindicated for MRI of the head, fear of enclosed spaces, or other standard contraindication to MRI (self-report checklist) or PET scanner.  11. Significant claustrophobia or other medical condition preventing subject from lying comfortably flat on his/her back for up to 2 hours in the MRI or PET scanner (self-report).  12. BMI > 35, imaging data acquisition is impaired with high-weight individuals).  13. Vision problems that cannot be corrected with glasses. 14. Judged by the principal investigator or his designee to be an unsuitable candidate for study participation.  ion Criteria:  -