A medicament comprising (I) brexpiprazole or a pharmaceutically acceptable salt thereof, and (II) nalmefene or a pharmaceutically acceptable salt thereof in combination, wherein brexpiprazole or a pharmaceutically acceptable salt thereof, and nalmefene or a pharmaceutically acceptable salt thereof are contained in a single preparation, or a pharmaceutical composition containing brexpiprazole or a pharmaceutically acceptable salt thereof and a pharmaceutical composition containing nalmefene or a pharmaceutically acceptable salt thereof are formulated for use in combination. The medicament is used for the prophylaxis or treatment of a substance-related disorder, preferably an alcohol-related disorder.
