find it difficult to stop smoking. Emerging genetic and pharmacogenetic studies have identified a potential role for gene variances in frustrated cessation attempts. One study, for example, found that smokers with a variant CYP2B6 gene have increased cravings for cigarettes following cessation and are about one and one half times more likely to relapse during treatment (Lerman et al. 2002). Information on genetic variants related to dopamine, serotonin, and nicotine metabolism, as well as other mechanisms that play important roles in nicotine addiction and maintenance, will be important to understand and better assist “hardcore” smokers and other smokers who have difficulty quitting.
There seems to be little doubt that a subset of the population of long-term smokers is more heavily addicted and less amenable to cessation inteventions. It is likely that these smokers are particularly vulnerable to nicotine addiction on the basis of predisposing personal characteristics and environmental stresses. These observations have two important implications: first, it is clear that specialized cessation interventions will be needed to assist them with quitting. Second, a realistic assessment of the prospects of achieving a substantial reduction in the prevalence of tobacco use must take the size of the “hardcore” target populations into account.
Smoking prevalence reflects the combined effects in any given period of the changes in the number of new smokers and in the number of smokers who have quit (Niaura and Abrams 2002). This chapter has provided an abridged overview of an extensive body of literature on the factors that affect the trends in smoking prevalence, with particular attention given to how the unique nature of nicotine addiction poses significant challenges to the success of tobacco control efforts.
At the center of the story emerging from this literature is the fact that nicotine addiction stimulates and sustains long-term tobacco use, with all of its serious health hazards and social costs. The literature also indicates that, although an overwhelming majority of smokers (90 percent) regret having begun to smoke, overcoming the grip of addiction and the associated withdrawal symptoms is difficult; most smokers must try quitting several times before they are successful. Progress in helping smokers who want to quit and achieve successful and permanent cessation requires that a variety of cessation technologies, both clinical and population-based, be readily available to the smoking population, that they be used, and that they be effective. This task is discussed further in Chapter 5 of this report.
While tackling the difficult challenge of helping addicted smokers quit, the fact that thousands of individuals begin smoking each day must also