Do former smokers respond to nicotine differently from never smokers? A pilot study

Nine former, 11 never, and 10 current smokers abstained from smoking for 16 h 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 randomized, double-blind, crossover design. To examine subjective effects, participants completed the POMS, ARCI, and other ratings before and after each dose. To examine nicotine reinforcement, participants reported preferences among the gums, reported gum vs. money choices plus, on a fourth day, underwent a double-blind self-administration test. Former and never smokers did not differ on any of the subjective or reinforcement outcomes. Current smokers did prefer and self-administer more nicotine than former and never smokers. These results contradict our prior finding that former and never smokers differ in their response to nicotine. We consider the present study a more valid test than our prior study for reasons outlined in the discussion. Our results fail to confirm theories that those destined to be smokers are more or less sensitive to nicotine and that nicotine use causes irreversible brain changes that increase nicotine reinforcement.