Sex differences in the subjective and reinforcing effects of cigarette nicotine dose

Rationale: Some research with novel nicotine delivery methods suggests that nicotine itself may be less reinforcing in women than in men. However, sex differences in the reinforcing effects of nicotine dose via cigarette smoking have received little attention. Objectives: Sex differences in the subjective and reinforcing effects of smoking were examined as a function of two cigarette nicotine dose levels (moderate - subjects' preferred brand, greater than or equal to0.7 mg yield; low - Carlton ultralight, 0.1 mg yield). Methods: Male and female smokers (n=30) participated in three sessions, the first two involving independent assessment (only one brand available), and the third involving concurrent assessment (both brands available), of subjective ratings (e.g. liking) and reinforcement for the two cigarette brands. Subjects were blind to the brand of each cigarette, and subjects abstained overnight prior to each session. Reinforcement was determined by responses on a computer task to earn single puffs on the designated cigarette. Results: Subjective ratings differed between the low versus moderate cigarette nicotine dose under both independent and concurrent assessment conditions, as expected. Notably, this dose difference was smaller in women than in men (i.e. significant sex by dose interactions). The dose effect on smoke reinforcement also was smaller in women than men, but only under the independent and not concurrent assessment condition. Conclusions: These results indicate that cigarette nicotine dose is a less important influence on the subjective and, under some conditions, reinforcing effects of smoking in women than in men.