Nicotine discrimination in men and women

Nicotine is the primary compound that maintains tobacco smoking behavior, a nd nicotine reinforcement may be related to its discriminative stimulus eff ects. Nicotine in novel form, isolated from tobacco smoke, is often reinfor cing in men but not in women, and clinical trials with nicotine replacement via gum or patch have often shown less efficacy in women vs, men trying to quit smoking. We hypothesize that this sex difference in nicotine reinforc ement or clinical efficacy may be related to reduced intensity of nicotine' s discriminative stimulus effects in women. Using formal drug discriminatio n procedures, we have found in several studies that discrimination respondi ng across nasal spray nicotine doses tends to be flatter for women than men (i.e., sex x dose interaction), suggesting reduced sensitivity to changes in dose. Results from the field of psychophysiology, involving detection of physiological changes, are generally consistent with our findings, and sug gest that the environmental context accompanying physiological, change is i mportant in understanding this sex difference. The implications of this sex difference for smoking cessation treatment and future research directions are presented. (C) 1999 Elsevier Science Inc.