Delay discounting and smoking: association with the Fagerström Test for Nicotine Dependence but not cigarettes smoked per day

Abstract

Delay discounting (DD) has been shown to be related to smoking status and-less consistently-frequency of cigarette use, but its independent relationship with dependence has not been examined. In this study, we evaluated the relationship between smoking and DD as a function of both smoking quantity and level of dependence controlling for use. A sample of 710 adults completed a DD task using hypothetical monetary rewards, and participants were classified according to smoking status. Current smokers were further characterized as light, moderate, or heavy smokers on the basis of number of cigarettes smoked per day (CPD). Dependence was assessed using the Fagerström Test of Nicotine Dependence (FTND), with the CPD item removed. Current smokers discounted delayed rewards more than never, occasional, or ex-smokers; the latter three groups did not differ. DD was not related to CPD, analyzed continuously or categorically. FTND scores independently predicted DD, controlling for CPD. Analysis of individual FTND items revealed a relationship between DD and morning smoking. When analyzed categorically based on a median split, individuals high in dependence discounted delayed rewards more steeply than low dependence, never, tried-it, and ex-smokers, while these groups did not differ from each other. These results suggest that DD among smokers is not simply the result of nicotine exposure, but may be an important marker for dependence, especially urgency to smoke in the morning.