Nicotine derived from the electronic cigarette improves time-based prospective memory in abstinent smokers

It is well established that nicotine improves, and deprivation impairs, cognitive performance and mood in smokers. Prospective memory (PM), remembering to execute a delayed intention at a given time point, is under-explored in smokers. Whilst a handful of studies have shown improved PM with nicotine, the effects of nicotine delivered via the electronic cigarette (e-cigarette) have not been investigated. This study explores whether, by comparison with placebo, nicotine delivered via the e-cigarette can improve PM, tobacco withdrawal symptoms and desire to smoke in abstinent smokers. Twenty smokers, abstinent for 8-10 h, each completed two experimental sessions under nicotine (18 mg) and placebo (0 mg) e-cigarette conditions. Participants completed a single-item desire-to-smoke scale and the Mood and Physical Symptoms Scale. PM was measured using the Cambridge Prospective Memory Test. Compared with placebo, the nicotine e-cigarette reduced the desire to smoke and tobacco withdrawal symptoms, and improved time-based but not event-based PM. There was a moderate, marginally significant negative correlation between PM performance during abstinence and nicotine dependence. This is the first study to show that nicotine derived via e-cigarette can improve PM in abstinent smokers, suggesting efficient nicotine delivery. The finding that the effect of nicotine was restricted to time-based rather than event-based PM is consistent with the view that nicotine acts to improve performance on strategic (effortful) rather than automatic processing. These findings add to the growing body of evidence that the e-cigarette can replace some of the effects of nicotine derived from tobacco smoking, thus highlighting its potential for smoking cessation.