Incentive-sensitization and addiction

The question of addiction concerns the process by which drug-taking behavior, in certain individuals, evolves into compulsive patterns of drug-seeking and drug-taking behavior that rake place at the expense of most other activities, and the inability ro cease drug-taking, that is, the problem of relapse. In this paper we summarize one view of this process, the incentive-sensitization view, which we first proposed in 1993. Four major tenets of the incentive-sensitization view are discussed. These are: (1) potentially addictive drugs share the ability to alter brain organization; (2) the brain systems that are altered include there normally involved in the process of incentive motivation and reward; (3) the critical neuroadaptations for addiction render these brain reward systems hypersensitive (sensitized) to drugs and drug-associated stimuli; and (4) the brain systems that are sensitized do nor mediate the pleasurable or euphoric effects of drugs (drug liking), but instead they mediate a subcomponent of reward we have termed incentive salience (drug wanting).