difficult to quit, experience withdrawal, and face huge personal costs from smoking, one could argue that almost all smokers should be diagnosed as dependent (see [10]) for related concerns); however, only about half of daily smokers meet DSM diagnoses for dependence. On the other hand, it is clear that amongst daily smokers there is considerable variability in withdrawal severity, relapse risk, and tobacco exposure [22]. One potential option is to adopt a quasi-continuous or continuous index of dependence [52].
