Effects of initial abstinence and programmed lapses on the relative reinforcing effects of cigarette smoking.

Cigarette smoking is the leading cause of preventable morbidity and mortality in the U.S., contributing to approximately 438,000 premature deaths yearly (“Annual Smoking-Attributable Mortality,” 2005). Each year millions try to quit smoking, but the majority fails within only a few days or weeks of the cessation effort (“Cigarette Smoking Among Adults,” 2005; Garvey, Bliss, Hitchcock, Heinold, & Rosner, 1992; Hughes et al., 1992; Hughes, Keely, & Naud, 2004). In a seminal study on predictors of smoking-cessation outcomes, Kenford et al. (1994) reported on data from two independent randomized clinical trials on the efficacy of active versus placebo transdermal nicotine therapy (i.e., the nicotine patch). Smoking status during the first 2 weeks of treatment, especially Week 2, was a robust predictor of smoking status at end of treatment and at 6-month follow-up in both studies. In the active patch conditions, for example, more than 80% of those who reported any smoking during Week 2 were smoking at 6-month follow-up. By contrast, 41% to 46% of those who abstained during Week 2 were still abstinent at follow-up. The authors gleaned two prediction rules from their findings: (a) “Any smoking in the first 2 weeks of treatment predicts both short-term and long-term failure,” and (b) “Total abstinence during the first 2 weeks of treatment was consistently correlated with sustained smoking success” (p. 593). Some aspects of this relation between initial abstinence and relapse risk are almost surely due to individual differences and not to dynamic changes in relapse risk during the cessation effort. Regarding individual differences, on average, those with more frequent smoking or greater dependence would be expected to relapse earlier than individuals without those characteristics, thereby assuring a decrease in relapse risk over time. That said, individual differences alone likely fail to offer a complete explanation for these relations between initial and later abstinence. It also seems likely that changes in factors that affect ability to abstain occur as a direct result of initial abstinence. Such changes in these factors may, in turn, make it more likely that a person will continue to abstain, thereby facilitating longer term abstinence. For example, the intensity of nicotine withdrawal decreases substantially during the initial weeks of smoking abstinence (Alessi, Badger, & Higgins, 2004; Hughes, Higgins, & Hatsukami, 1990). Although such dynamic changes during an initial period of abstinence may act to directly lower relapse risk, rigorous experimental research examining this topic has been largely missing from the field. An important obstacle to conducting such experimental research has been the challenge of gaining experimental control over the duration of prior abstinence. Without such control, the influences of dynamic changes that occur during initial abstinence risk being confounded with individual differences among those who achieve different durations of initial abstinence. Previous research has attempted to surmount that obstacle by using contingency management to gain experimental control over abstinence (Alessi et al., 2004; Heil, Alessi, Lussier, Badger, & Higgins, 2004; Lussier, Higgins, & Badger, 2005; Roll, 2005; Yoon, Higgins, & Bradstreet, 2007). Researchers have also focused on investigating relations between early and later smoking abstinence among smokers who are willing to try to quit as part of a study but are not now trying to quit longer term (e.g., Stitzer, Rand, Bigelow, & Mead, 1986). Using this target population increases the likelihood that any changes in smoking frequency are due to the experimental variables under investigation as opposed to individual reasons for wanting to quit that may be unstable over time. In a prior study addressing how early abstinence influences later abstinence, contingency management in the form of monetary payments delivered contingent on biochemically verified smoking abstinence was used to create different histories of prior abstinence such that participants either largely abstained during three 5-day experimental periods or abstained only during the last of those periods (Heil et al., 2004). Abstinence levels during the third period were significantly higher in those with a history of abstaining compared to those who were abstaining for the first time, suggesting that a history of prior abstinence facilitated later abstinence. An important next step in this series of studies included a direct test of the relative reinforcing effects of smoking following different durations of smoking abstinence (Lussier et al., 2005). Study participants were randomly assigned to receive abstinence-contingent payments for either 1 day (1C), 7 days (7C), or 14 days (14C) and then completed a 3-hr test of the relative reinforcing effects of smoking. The test involved participants making a maximum of 20 discrete-trial choices between earning two puffs on a cigarette or $0.25. Results indicated that the relative reinforcing effects of smoking were significantly lower among those assigned to the 14C compared to the 7C and 1C conditions. That is, participants in the 14C (M = 0.52, SEM = 0.28) condition made significantly fewer choices of the smoking option than those in the 7C (M = 2.19, SEM = 0.60) or 1C (M = 2.71, SEM = 0.63) conditions, and a smaller proportion of participants in the 14C (19%) condition chose to smoke at least once compared to those in the 7C (57%) and 1C (62%) conditions. The differences in smoking preference as a function of different durations of smoking abstinence noted by Lussier et al. were recently replicated in a follow-up study also conducted in our laboratory (Yoon et al., 2007). In the present study we sought to extend these prior observations by examining the effects of programmed smoking lapses during the initial 2 weeks of smoking cessation on the relative reinforcing effects of smoking. Although smoking even a few puffs on a cigarette during a cessation effort has been reported to increase the probability of relapse (Kenford et al., 1994), there has been little experimental analysis of this association between brief smoking lapses and relapse risk. This study represents an effort to examine in a controlled setting how such lapses may increase the probability of relapse. Examining how lapses may interfere with dynamic changes in factors such as withdrawal level, mood, relative reinforcing effects of smoking, and so on that occur during initial abstinence may provide insight into how to devise more effective interventions for the early hours and days of a quit attempt when the vast majority of relapse back to smoking occurs.