This study examines the effects of the medication tolcapone among individuals who regularly drink alcohol. Participants in this study will be randomly assigned to take either tolcapone or a matched placebo for 7 days. There are 2 study visits, both of which include an MRI scan, and a debriefing session. This study does not involve alcohol treatment. Interested individuals must be referred for participation by the Charleston Alcohol Research Center Clinical Intake and Assessment Core. For more information, call 792-1222 or email firstname.lastname@example.org.