Background: Whether smokers with a past history (PH) but not current history of alcohol dependence are more nicotine dependent than smokers with no such history (NH) is unclear. The present study was an experimental test of this hypothesis.
Method: Twenty PH and 10 NH smokers abstained from smoking for 16 hr on each of 4 days. On each of 3 days, participants received three doses per day of 0, 2, or 4 mg nicotine gum in a within-subjects, randomized, double-blind, crossover design. To examine subjective effects, participants completed the Profile of Mood States, Addiction Research Inventory, and other ratings before and after each dose. To examine nicotine reinforcement, participants reported preference among the gums, reported on money versus gum choices, and, on the 4th day, underwent a double-blind self-administration test.
Results: Across the 21 subjective measures, with one exception, PH and NH smokers did not differ in subjective response to nicotine. However, across all three reinforcement measures, nicotine was a more potent reinforcer in PH than NH smokers.
Conclusions: These results provide a behavioral mechanism to explain prior findings that PH smokers are more nicotine dependent than NH smokers.