Evidence for the Incentive Sensitization Model of Addiction in Adolescent Smokers

The Incentive Sensitization Theory of Addiction (I-S) was first proposed by Robinson and Berridge in 1993, and since then has garnered support in a variety of drugs of abuse. The theory postulates that over time and repeated administration, and through learning processes, drugs of abuse produce incremental and measurable changes within the mesolimbic dopaminergic system, which manifests as increases in appetitive behavior (“wanting”). Interestingly, these changes may occur independently from systems that regulate the hedonic evaluation of the substance (“liking”). This process results in a growing dissociation over time between an individual’s ratings of “liking” and “wanting”, and that this dissociation may be predictive of maladaptive substance use. A number of issues have prevented researches from examining this theory within the context of cigarette smoking, chiefly that adults have already reached a ceiling in terms of “wanting” and that the variance in measured “liking” has already been lost. This study attempted to lend support for the I-S model within a population of adolescent smokers, and found that early on in the course of cigarette use, ratings of “liking” were associated with cigarette consumption, but over time, “wanting” was the only factor that was predictive of use. Future directions include more nuanced measures of the pleasure effects of nicotine as well as “wanting”, and more momentary assessments of these effects to garner a larger, more varied sample.