Measuring Distress Tolerance With Functional MRI

Background: \- People who are in treatment for substance abuse often feel distress during the withdrawal period and afterward. Some individuals feel distress more acutely than others, and this distress has been linked to poor treatment outcomes and increased risk of relapse in smokers, alcoholics, and cocaine- and heroin-dependent individuals. More research is needed on the effects of distress on the brain, particularly in individuals who are seeking treatment for substance abuse. Researchers are interested in using functional magnetic resonance imaging (fMRI) scanning to study distress tolerance in both substance users seeking treatment and healthy non-drug-using volunteers. Objectives: \- To use functional magnetic resonance imaging to study the effectiveness of a distress tolerance assessment. Eligibility: \- Individuals between 18 and 50 years of age who are either cocaine dependent or healthy non-drug-using volunteers. Design: * This study involves an initial screening visit and a scanning visit, with four followup visits. * Participants will be screened with a medical history and physical examination, as well as blood samples and questionnaires about mood and past and current drug use. * Participants will have a structural MRI scan of the brain to provide a baseline reading for comparison. Participants will then have an fMRI scanning session, which will include both the distress tolerance assessment and relevant control tasks. Heart rate, blood pressure, and other physical reactions will be monitored throughout the scan. Participants will also provide blood and saliva samples to measure stress hormone levels. * Participants will be eligible to have followup assessments with fMRI scanning 1, 3, 6, and 12 months after the scanning visit.