Objectives: The purpose of this work was to identify characteristics that predict progression from the first inhalation of a cigarette to dependence. We studied a cohort of 1246 public school 6th-graders in 6 Massachusetts communities (mean age at baseline: 12.2 years).
Methods: We conducted a 4-year prospective study using 11 interviews. We assessed 45 risk factors and measured diminished autonomy over tobacco with the Hooked on Nicotine Checklist and evaluated tobacco dependence according to the International Classification of Diseases, 10th Revision. Cox proportional-hazards models were used.
Results: Among 217 youths who had inhaled from a cigarette, the loss of autonomy over tobacco was predicted by feeling relaxed the first time inhaling from a cigarette and depressed mood. Tobacco dependence was predicted by feeling relaxed, familiarity with Joe Camel, novelty seeking, and depressed mood.
Conclusions: Once exposure to nicotine had occurred, remarkably few risk factors for smoking consistently contributed to individual differences in susceptibility to the development of dependence or loss of autonomy. An experience of relaxation in response to the first dose of nicotine was the strongest predictor of both dependence and lost autonomy. This association was not explained by trait anxiety or any of the other measured psychosocial factors. These results are discussed in relation to the theory that the process of dependence is initiated by the first dose of nicotine.