Cocaine and alcohol addiction are serious health problems with no available medical treatment for preventing relapse. Past research has shown that individuals who are addicted to both cocaine and alcohol typically respond poorly to conventional substance abuse treatment. Little attention has been directed towards how best to treat these individuals. Naltrexone is a medication that is currently used to treat drug and alcohol addiction. It acts by blocking the "high" feeling produced by drugs and alcohol. Modafinil, another medication, enhances mood, increases energy, and improves concentration in people with narcolepsy. Preliminary research has shown that it may produce similar effects to cocaine, thereby potentially countering the symptoms of cocaine withdrawal. Cognitive Behavioral Coping Skills Therapy (CBT), a form of therapy that aims to alter an individual's patterns of behavior and drug use, is also an important component of substance abuse treatment. The purpose of this study is to compare the effectiveness of CBT plus placebo, CBT plus modafinil, CBT plus naltrexone, and CBT plus a combination of modafinil and naltrexone at reducing cocaine and alcohol use in individuals addicted to both substances.