Initial reactions to tobacco use and risk of future regular use.

INTRODUCTION: Studies suggest that initial smoking pleasure influences future smoking behavior. We investigated how initial reactions to cigarettes or Swedish smokeless tobacco (snus) were associated with future use among 10,708 adults from the Swedish Twin Registry.
METHODS: The Early Smoking Experience questionnaire captured physiologic reactions to initial tobacco use. Binary recursive partitioning (BRP) identified combinations of initial reactions predictive of regular tobacco use. Analyses, stratified by sex, were conducted separately among those who experimented with only cigarettes (EC), only snus (ES), and both products (EC+S).
RESULTS: Among EC, 39.8% of men and 43.7% of women became smokers, while among ES, 78.6% of men and 53.7% of women became snus users. Among EC+S, 31.3% of men and 20.0% of women became dual users. BRP identified different reactions as predictive of future smoking for men (buzz) and women (dizziness, difficulty inhaling). No initial reaction predicted future snus use among men, but pleasant sensations, later age at first use, and relaxation predicted future snus use for women. Among EC+S, future exclusive use of either product was associated with a favorable initial reaction to that product. Dual users experienced higher prevalence of pleasant reactions and lower prevalence of unpleasant reactions in response to both products.
CONCLUSIONS: Our findings support that those who progress to regular tobacco use may be sensitive to the rewarding effects of nicotine but suggest that initial reactions differ by tobacco type. A high proportion of men became regular snus users regardless of initial reactions.