Disclosed is a novel combination therapy to reduce or prevent the acquisition of a conditioned response in a mammal comprising administering to the mammal a therapeutically effective amount of an aldehyde dehydrogenase (ALDH-2) inhibitor compound, such as a compound of Formula (I), in combination with a substance that produces the conditioned response, such as a medication containing a dopamine-producing agent such as an opioid, whereby the combination acts to reduce or prevent the acquisition of a conditioned response, and the deleterious side-effect of misuse, dependence, abuse, and/or addiction.