PTSD is a psychiatric illness that occurs following a traumatic event in which there was threat of injury or death to an individual. Common symptoms of PTSD include anxiety, stress, and tension. Some individuals with PTSD use benzodiazepines, a type of sedative medication, or alcohol to alleviate the anxiety associated with the disorder. Past research has shown that the negative feelings experienced by individuals with PTSD may increase the reinforcing effects of antidepressant drugs. Feelings of anxiety act as a stimulus, which leads to drug use; in turn, the anticipated or actual decrease in distress reinforces the drug-taking behavior. Greater amounts of sedative drugs are then needed to decrease subsequent stress and anxiety. The purpose of this study is to understand how negative emotional states affect the reinforcing effects of sedative drugs in individuals with PTSD.

This study will enroll two types of individuals, both of whom have been exposed to an emotional trauma and report using alcohol to reduce emotional distress but who differ in their subsequent development of PTSD. Participants will take part in an initial screening session which will include a physical examination, standardized psychological questionnaires, and review of medical and drug histories. Once enrolled, each participant will take part in 8 experimental session days, with each day of testing separated by at least 48 hours. At the beginning of each session, a breathalyzer and urine test will be used to screen for the presence of alcohol and drugs. On Day 1, participants will take part in an orientation session to familiarize themselves with the laboratory and study procedures. On Days 2 through 4, participants will receive varying doses of alcohol, a placebo drink, a placebo drug, and alprazolam, a type of benzodiazepine medication. On Days 5 through 8, participants will take part in experimental challenges designed to induce various emotional states, including arousal, anxiety, aggression, and anger. They will also complete a monetary reward task to measure the reinforcing effects of drugs. Participants will complete questionnaires several times each day to assess anxiety, anger, drug effects, and drug cravings. Heart rate will be monitored with an electrocardiogram, and electrodes placed on the skin will measure other physiologic measures throughout each session. Participants will receive compensation for completing each experimental session.