Patient description: A 42-year-old healthy woman came to the clinic to have her flu shot in early October. She works in a rehab center and has no underlying disease. It's her first time getting the vaccine this year. She is married for 5 years and uses barrier methods of contraception. Her menstrual cycle is irregular. She does not smoke. She is not on any medications. She exercises regularly for 30 minutes a day at least 5 days a week. She has no history of allergies to any food or drugs. Her past surgical history is significant for tonsillectomy and she is otherwise healthy.

Clinical trial eligibility criteria: eligible ages (years): 21.0-60.0,  Alcohol Drinking Male and female participants between 21-60 years of age. (assessment: identification provided to Clinical Center Admissions office) Smoking status: 1. Smokers will have a history of at least 1 year of daily smoking, defined as individuals who smoke more than 20 uses of nicotinic products/week on average, and a cotinine level, measured by the NarcoCheck PreDosage Nicotine Test (PNT) test, of >= 2. [assessment: Smoking history questionnaire, Additional medical history, PreDosage Nicotine test] 2. Non-smokers with no history of smoking in the past year and less than 20 uses of nicotinic products lifetime.(assessment: smoking history questionnaire, Additional medical history) for women: Use of adequate method of birth control during the study, if female is sexually active and is not surgically sterilized. Adequate methods of contraception use of oral contraceptives; use of barrier method of contraceptive; use of an approved IUD or other long-acting reversible contraceptive (LARC); have a male sexual partner who is surgically sterilized; or have exclusively female sexual partner(s). Justification: To minimize the risk of administering alcohol to pregnant women, given the known effects of alcohol exposure on fetuses. (assessment: medical history)  Current or prior history of major medical illness, including CNS, cardiovascular, respiratory, gastrointestinal, hepatic, renal, endocrine, or reproductive disorders. Justification: Many illnesses may alter the neuropsychological effects of alcohol as well as MRI measures. (assessment: clinically significant findings on medical history and physical exam, ECG, laboratory tests) Positive hepatitis (A, B antigen, or C), or HIV test at screening. Justification: Hepatitis can alter liver function and alcohol pharmacokinetics. HIV infection can alter brain function. (assessment: laboratory tests) Current (past 12 months) history of psychiatric disorders, including depressive disorder, bipolar disorder, or anxiety disorders. Justification: Concurrent psychopathology can alter brain function and alcohol response. (assessment: SCID interview) Lifetime history of psychotic disorders, obsessive compulsive disorder (OCD), post-traumatic stress disorder (PTSD), or eating disorder. Justification: These disorders can have long-term effects on brain function and alcohol response. (assessment: SCID interview) Current or lifetime diagnosis of alcohol or substance use disorder. Justification: History of alcohol or substance use disorder will impact brain function and alcohol response. (assessment: SCID interview) Currently seeking treatment for alcohol use disorders. Justification: It would be unethical to administer alcohol to individuals seeking treatment for alcohol problems. Also, this study does not provide treatment for individuals with alcohol use disorder. (assessment: medical history) History of significant withdrawal symptoms or presence of clinically significant withdrawal symptoms (Clinical Institute Withdrawal Assessment (CIWA) score > 8) at screening. Justification: Withdrawal symptoms would be indicative of alcohol use disorder, which is already an  Additionally, withdrawal symptoms would be a major safety concern for participants, and a major confound in the assessment of alcohol response and brain function. (assessment: CIWA assessment) Non-drinkers (alcohol-na(SqrRoot) ve individuals or current abstainers) or individuals with no experience drinking 5 or more drinks on one occasion in their lifetime. Justification: It would be unethical to administer alcohol to individuals that do not drink alcohol. (assessment: medical history) Positive result on urine drug screen or positive breathalyzer during screening visit. Positive urine drug screen or breathalyzer reading during more than 1 study visit will result in participant withdrawal from the study. Justification: Current or recent exposure to alcohol or drugs of abuse could impact brain function and alcohol response. (assessment: laboratory tests and breathalyzer test performed at screening or update visit under 14-AA-0181 most proximal to enrollment)