This study is a phase IV, two-arm, randomized, double-blind, placebo-controlled study to
assess whether individuals identified as primarily reward drinkers are significantly more
likely to reduce heavy drinking if they receive XR-NTX than a matching placebo injection.
Study subjects will receive monthly injections of long-acting injectable naltrexone 380 mg (4
mL) or matching placebo. All subjects will also receive 4 sessions of Medical Management
(MM). Post-treatment follow-up visits will be conducted at 4 weeks after the scheduled
completion of treatment.