A second potential modification of DSM criteria lies in negative reinforcement models of addiction (e.g. [12,13]) that emphasize the primacy of tolerance and withdrawal (see [14]). In short, these models posit that drug dependence is marked principally by these two features, which are the result of the homeostatic adaptation of the nervous system to chronic drug use. In its definition of substance dependence, the DSM-IV underscores tolerance and withdrawal, and dictates that the presence of these symptoms indicate ‘physiological dependence’ [6]. Although neither tolerance nor withdrawal are necessary or sufficient for a diagnosis of dependence in the DSM-IV, nicotine dependence criteria based on models of negative reinforcement might focus solely on these two symptoms.
