Refining the tobacco dependence phenotype using the Wisconsin Inventory of Smoking Dependence Motives.

The construct of tobacco dependence is important from both scientific and public health perspectives, but it is poorly understood. The current research integrates person-centered analyses (e.g., latent profile analysis) and variable-centered analyses (e.g., exploratory factor analysis) to clarify the latent structure of nicotine dependence and to guide distillation of the phenotype. Using data from 4 samples of smokers, latent profiles were derived using the Wisconsin Inventory of Smoking Dependence Motives subscale scores. Across all 4 samples, results revealed a unique latent profile that had relative elevations on 4 subscales (Automaticity, Craving, Loss of Control, and Tolerance). Variable-centered analyses supported the uniqueness of these 4 subscales as they constituted a distinct common factor and were the strongest predictors of relapse and other dependence criteria. Conversely, the remaining 9 motives carried little unique predictive validity regarding dependence. Applications of a factor mixture model further supported the presence of a unique class of smokers in relation to a common factor underlying the 4 subscales. The results suggest that a pattern of smoking that is heavy, pervasive, automatic, and relatively unresponsive to instrumental contingencies is a necessary and sufficient condition for severe nicotine dependence.