This study will evaluate naltrexone and cognitive-behavioral therapy treatments for alcohol dependence and post-traumatic stress disorder (PTSD). Subjects will be randomly assigned a 6-month treatment of either: 1) naltrexone alone, 2) naltrexone with PTSD psychosocial therapy, 3) a placebo with PTSD psychosocial therapy, or 4) placebo alone. An enhanced medication management intervention will accompany all treatment conditions. Follow-up assessments will be completed at 9 and 12 months after treatment.