Background: Current theoretical models of nicotine dependence assume a close relationship between use and dependence; however, previous data suggest that many daily smokers fail to develop nicotine dependence.
Objectives: To determine what percentage of daily smokers fail to meet DSM-IV criteria for nicotine dependence within their lifetime, how non-dependence relates to duration and quantity of cigarette use, and whether other tobacco use and/or specific dependence criteria differentiate never-dependent and dependent smokers.
Methods: Cross-sectional data collected via personal interview from a nationally representative sample of 8213 past year daily smokers were analyzed.
Results: Approximately 39.4% of daily smokers never reached nicotine dependence. While the probability of remaining non-dependent decreased with smoking quantity and duration since the onset of daily smoking, a substantial portion of individuals (37.7%) who reported smoking >or=10 cigarettes per day and began smoking daily >or=10 years prior, remained never nicotine dependent.
Conclusions: The absence of nicotine dependence in heavy daily smokers may result from limitations in the measurement of dependence and/or nicotine exposure. Alternatively, some individuals may be relatively resistant to becoming nicotine dependent despite extensive use. The latter explanation would have important implications for understanding the nature of nicotine dependence.