Effects of short-term nicotine deprivation on decision-making: Delay, uncertainty and effort discounting

Experimental evidence suggests that when opioid-dependent drug users are deprived of heroin, they become more likely to behave impulsively on a computer task. The current study examined whether nicotine deprivation has similar effects in cigarette smokers, causing an increase in impulsive decision-making. Simultaneously, the impact of deprivation on several other related decision-making tasks was assessed. Eleven smokers ( greater than or equal to15 cigarettes/day) participated in two experimental sessions. For one session, they smoked as usual until the session began. For the other, participants did not smoke for 24hr. Abstinence was verified using levels of breath carbon monoxide and urinary cotinine. During each session, they completed computer tasks that assessed impulsivity by measuring the tendency to choose small, immediate rewards (cigarettes or money) over US$10 available following a delay, as well as tasks in which smokers chose between small, certain, easily obtained rewards and US$10 whose availability was uncertain or required high levels of effort to obtain. Deprivation increased preference for immediate cigarettes over delayed money, but did not alter preference for immediate money over delayed money. These findings indicate that short-term nicotine abstinence does increase impulsive decision-making, but only when the impulsive choice is drug-related. Increases were not related to a general increase in the value of immediate rewards per se or a general increase in aversion to delayed rewards. Decision-making in the other tasks followed a similar pattern: Deprivation increased preference for the cigarette alternative but did not alter the decision-making processes for nondrug rewards.