The project will use a 2x2 design to assess the efficacy of naltrexone for treating subjects who are both cocaine and alcohol dependent and who will receive either CBT or BRENDA alone or in combination with naltrexone. There will be 300 DSM-IV cocaine-alcohol dependent male and female subjects randomized to one of four groups (75 subjects per group). Subjects will be randomized to either 150mg/day naltrexone or placebo and to receive either CBT (a type of cognitive behavior therapy derived from relapse prevention principles), or a new primary-care basedmodel, BRENDA, comprised of strategies for enhancing motivation and treatment compliance. All subjects will receive one of the four combinations of medication and psychosocial treatment. The length of the study for each subject includes one week of screening/baseline assessments, 12 weeks of double-blind, placebo-controlled naltrexone treatment combined with one of two psychosocial treatments, and a 6-month and 12-month follow-up visit. Following successful completion of detoxification (abstinence from alcohol and cocaine for 7 days), informed consent will be signed, and Week 1 will be devoted to completing screening and baseline measures. In Week 2, subjects will be randomly assigned to medication/ psychosocial treatment combination. Following completion of the 12-week, double-blind treatment trial, subjects will be evaluated at 6-month and 12-months post-treatment visits.