Measures of impulsivity in cigarette smokers and non-smokers

Rationale: Drug users are thought to be more "impulsive" than non-users. Objectives: This study examined whether regular smokers are more impulsive than never smokers using personality and behavioral measures of impulsivity. Methods: Twenty regular smokers (greater than or equal to 15 cigarettes/day) and 20 never smokers were recruited. Participants completed five personality questionnaires to assess impulsivity: Adjective Checklist, Barratt's Impulsivity Scale, the Tridimensional Personality Questionnaire, Eysenck's Personality Questionnaire, and the Sensation-Seeking Scale. Participants also performed three behavioral choice tasks designed to assess impulsivity. In the delay task, participants chose between small, immediate and large, delayed monetary rewards. Impulsivity was defined as a relative preference for the small, immediate alternative. In the probability task, participants chose between small, certain and large, uncertain monetary rewards. Impulsivity was defined as a relative preference for the large but more risky alternative. In the work task, participants chose between small monetary rewards obtained by performing a negligible amount of work and a larger amount of money requiring more work. Impulsivity was defined as a relative preference for the smaller, easier alternative. Results: On the personality questionnaires, smokers had statistically higher impulsivity scores on most scales. On the behavioral choice tasks, smokers chose small, immediate money over large, delayed money more frequently, signifying greater levels of impulsivity. There were no differences between the groups' choices on the other tasks. Correlations between questionnaire and task data were small, as were correlations between data from each task. Conclusions: Together, these results indicate that the smokers were more impulsive than never smokers.