[Reconsideration of nicotine and other substance dependence: a clue from dependence-related mentation including reward, motivation, learning, delusion and hallucination toward understanding the concept of non-substance-related addiction].

Abstract

Nicotine produces core symptoms of substance dependence (craving and withdrawal) without any psychotic symptoms. The psychopharmacological structure of craving is hypothesized to be constituted by three components: the primary reinforcing property of a substance, the secondary reinforcing property of that substance (conditioned aspects of the environment, such as contextual or specific cues associated with substance taking), and the negative affective motivational property during withdrawal (i.e. the desire to avoid the dysphoric withdrawal symptoms elicits craving). Among the three components, the primary reinforcing property of a substance forms the most fundamental factor for establishing substance dependence. Sensitization or reverse tolerance observed in locomotor activity of animals, which had been believed to be a methamphetamine psychosis model, is demonstrated to reflect the establishment of conditioned reinforcement. Finally, non-substance-related addiction such as gambling, internet, and sex is discussed. From the aspect of the above hypothetical psychopharmacological structure of craving, the most significant difference between substance dependence and non-substance-related addiction is that the primary reinforcing property of non-substance reward is relatively intangible in comparison with that of a substance of abuse.