Clinical-Genetic Variation in GABA/Alcohol Sensitivity

Inclusion Criteria: * The subject is male or female with at least one Hispanic birth parent of Mexican ancestry, 21-25 years of age, and able to read the English-language consent form. * The subject self-reports current use of 3-30 standard drinks * The subject is in good physical health as determined by history, physical and laboratory studies of hematology and chemistry * The subject has a Body Mass Index (BMI) between 20-28 * The subject is not concurrently using psychoactive medication or illicit drugs * If subject is female, she is not pregnant (determined by weekly urine pregnancy screens), is practicing barrier or chemical methods of birth control, and not nursing babies Exclusion Criteria: * The subject meets DSM-IV criteria for any lifetime history of alcohol dependence, or dependence or abuse on any other drug in the past two years excepting tobacco dependence * The subject currently meets DSM-IV for any other psychiatric (Axis I) disorder, excepting tobacco dependence * The subject cannot consistently provide alcohol-free breath samples and drug-free urine samples * The subject uses \> 20 cigarettes per day or \> 500 mg caffeine per day * The subject's physical exam, lab tests, and medical histories indicate medical illness requiring treatment or interacting with the alcohol or benzodiazepine treatments * The subject has a sleep apnea or narrow angle-glaucoma (contraindications for benzodiazepines) * The subject reports extreme hypersensitivity or allergic reactions to benzodiazepines or unusual hypersensitivity to multiple medications * The subject is unwilling or unable to consent to all experimental procedures including confidential family history interviews and genetic testing specified by the protocol