Modafinil and Naltrexone to Reduce Cocaine and Alcohol Dependence (Mod-Nal)

4.1 Inclusion Criteria Male and females, 18 years of age or older. Meets DSM-IV criteria for current diagnoses of cocaine and alcohol dependence, determined by the SCID-IV. In the past 30 days, used no less than $200-worth of cocaine and meets the following drinking criteria as measured by the Timeline Followback (TLFB) (Sobell, 1995): drank within 30 days of intake day, reports a minimum of 48 standard alcoholic (avg. 12 drinks/wk) in a consecutive 30-day period over the 90-day period prior to starting intake (i.e., a minimum of 40% days drinking), and has 2 or more days of heavy drinking (defined as 5 or more drinks per day in males and 4 or more drinks per day in females) in this same pre-treatment period. 72 consecutive hours of abstinence from alcohol, determined by self-reports and confirmed by a negative breathalyzer tests, and a Clinical Institute Withdrawal Scale for Alcohol (CIWA-AR) (Sullivan, 1989) score below eight. Subjects will be encouraged to achieve 72 consecutive hours of abstinence, however, subjects who have achieved between 48 and 72 consecutive hours of abstinence will be included with the approval of the principal investigator. We anticipate that these subjects will comprise less than 5% of total enrolled subjects. Subjects will be given 2 additional weeks beyond the screening week to attain the appropriate period of alcohol abstinence prior to randomization. Lives a commutable distance from the TRC and agrees to attend all research visits including follow-up visits. Speaks, understands, and prints in English Ability to give informed consent Exclusion Criteria Abstinent from cocaine or alcohol for 30 consecutive days prior to signing consent form. Meets DSM IV criteria for dependence on any substance other than cocaine and alcohol (except nicotine), determined by the SCID. Needs treatment with any psychoactive medications including any anti-seizure medications (with the exception of diphenhydramine used sparingly, if necessary, for sleep). Meets current or lifetime DSM-IV criteria for schizophrenia or any psychotic disorder or organic mental disorder. Subject meets current DSM-IV diagnosis of any other clinically significant psychiatric disorder that will interfere with study participation. Has evidence of a history of significant hematological, pulmonary, endocrine, cardiovascular, renal or gastrointestinal disease (including a history of myocardial infarction, mitral valve prolapse, left ventricular hypertrophy, uncontrolled hypertension). Severe physical or medical illnesses such as AIDS, active hepatitis, significant hepatocellular injury as evidenced by elevated total bilirubin levels (>1.3 mg/dl),or elevated levels (over 4.5x normal) of aspartate aminotransferase (AST), and serum glutamic-pyruvic transaminase (SGPT) after the required 3 days of abstinence. Use of an investigational medication in the 30 days prior to randomization. History of hypersensitivity to modafinil or naltrexone Receiving chronic therapy with any drug known to interact adversely with either modafinil or naltrexone including propranolol, phenytoin, warfarin, diazepam Took a monoamine oxidase inhibitor within 30 days of randomization. Is female and tests positive on a pregnancy test, is contemplating pregnancy in the next 6 months, is nursing, or is not using an effective contraceptive method (if relevant). Acceptable methods of contraception include barrier methods (diaphragm or condom with spermicide, female condom), intrauterine progesterone contraceptive system, levonorgrestrel implant, and medroxyprogeterone acetate contraceptive injection, copper IUD, vaginal contraceptive film, cervical cap, contraceptive foam. Current use of an oral contraceptive without other acceptable barrier method of contraception. Received therapy with any opiate substitute (methadone, LAAM, buprenorphine) within 60 days of randomization