Sex differences in nicotine versus nonnicotine reinforcement as determinants of tobacco smoking

Nicotine replacement is less effective for smoking cessation in women than men. A possible explanation is that nicotine intake may be a less reinforcing consequence of tobacco smoking in women versus men, whereas nonnicotine aspects of smoking may be more reinforcing. Recent research suggests that nicotine self-administration is less robust in women, that women may reduce their smoking to a lesser degree following nicotine preloading, and that women may be less sensitive to interoceptive stimulus (or subjective) effects of nicotine. There does not seem to be a generalized insensitivity or hypersensitivity to nicotine in women. In contrast, women may be more responsive to the nonnicotine stimuli of smoking. These findings are consistent with other research indicating that women are less able than men to detect interoceptive stimuli (physiological changes). If confirmed, these sex differences could have important clinical implications; nicotine replacement may warrant a less important role in smoking cessation, whereas interventions to counter the nonnicotine aspects of smoking may need to be emphasized.