This 27-week double-blind, placebo controlled treatment is designed to evaluate dextroamphetamine sulfate (sustained release) as an adjunct in concurrent cocaine and opiate dependent patients. All subjects will receive methadone. For the treatment of cocaine dependence, subjects will receive one of 2 doses of dextroamphetamine (15 or 30mg) or placebo. After 4 weeks of treatment the dose level of dextroamphetamine is doubled (30 or 60mg). This dose is maintained for 20 weeks; during which subjects attend twice weekly visits to the clinic and receive weekly cognitive behavioral therapy. Follow up evaluations will be conducted out to 3 months post treatment. Subjects will be assisted in transferring to Houston area methadone clinics to maintain treatment for opiate dependence following treatment completion.