This was a Phase 3, multicenter, randomized, double-blind, placebo-controlled study conducted in subjects diagnosed with alcohol dependence as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th Ed. (DSM-IV). Subjects were randomized (2:2:1:1) to receive intramuscular (IM) injections of Medisorb® naltrexone 190 mg, Medisorb naltrexone 380 mg, placebo for Medisorb naltrexone 190 mg, or placebo for Medisorb naltrexone 380 mg (VIVITROL®). Study drug was administered every 4 weeks for a total of 6 injections.