This study was conducted to further examine changes in the relative reinforcing effects of smoking during initial smoking abstinence by examining the influence of brief smoking lapses. As was mentioned above, gaining experimental control over smoking abstinence has been an important obstacle to conducting experimental studies that examine what dynamic changes may occur during an initial period of abstinence that may reduce relapse risk. The results from the present study and prior studies offer compelling support for the effectiveness of contingency management for surmounting that obstacle (e.g., Alessi et al., 2004
; Heil et al., 2004
; Heil, Tidey, Holmes, Badger, & Higgins, 2003
; Lussier et al., 2005
; Yoon et al., 2007
). The differences in breath CO levels in the 14C and 1C conditions during Days 1 to 13 of the present study illustrated a striking degree of experimental control over smoking, a behavior that by any standard is very difficult to control for more than a few hours. Of course, the precipitous change in CO levels between Days 13 and 14 corresponding to the change from noncontingent to abstinence-contingent reinforcement in the 1C condition further illustrated the effectiveness of the reinforcement contingencies to bring smoking under experimental control. The purpose for exerting such control in the present study was strictly scientific, but the abstinence-contingent reinforcement methods that have been developed as part of this research effort have been successfully extended to important clinical applications, including, for example, the promotion of smoking cessation among pregnant women (Higgins et al., 2004
) and opioid-dependent patients (Dunn, Sigmon, Thomas, Heil, & Higgins, 2008
There was no discernible evidence in the present study that the programmed smoking lapses disrupted control over smoking abstinence by the abstinence-contingent reinforcement contingencies. That is encouraging in that it suggests that regular exposure to smoking paraphernalia or brief smoking lapses need not scuttle a cessation effort when there are strong incentives to sustain abstinence, as there were with the contingency management intervention employed in the current study. Many of the difficult-to-treat populations with whom contingency management procedures for smoking cessation hold promise reside with other cigarette smokers, which makes exposure to secondhand smoke and the probability of relapse more likely (Solomon et al., 2007
). The present results suggest that at least for the period while the reinforcement contingencies are in place, abstinence may still be sustainable in those populations and settings.
The results observed in the preference sessions suggest that under conditions in which the contingencies for sustaining abstinence are weaker, a history of recent lapses may increase the probability of smoking. Even though the observed changes in smoking were admittedly modest, they were very much in the predicted direction and graded in an orderly manner, suggesting that they were not likely a spurious observation. Interpreted within the context of other studies on this topic (Alessi et al., 2004
; Lussier et al., 2005
; Yoon et al., 2007
), the results observed among abstinent participants in the 14C 8-puff condition suggest that lapses may interfere with the decreases in the relative reinforcing effects of smoking that otherwise occur from sustaining abstinence through the initial weeks of a cessation effort. That is, despite having abstained from smoking for 2 weeks, the mean likelihood of smoking in the preference test among the total abstainers in the 14C 8-puff condition was almost 1.75-fold higher than their counterparts in the 14C 0-puff and 14C 1-puff conditions and more comparable to those in the 1C 0-puff condition, who had only abstained from smoking for 1 day. We saw no difference between the 14C 8-puff condition and the other 14C conditions in participant-rated withdrawal, ease of abstaining, or other outcome measures that would provide insight into how lapses may increase smoking preference. A more detailed understanding of the mechanisms by which lapses during a period of smoking abstinence may increase relapse risk is important for the development of more effective relapse-prevention interventions.
There was no evidence in the present study of differences in smoking preference or any other measure between participants in the 14C 1-puff and 14C 0-puff conditions. Of course, participants in the 14C 0-puff condition were regularly exposed to smoking paraphernalia in the lapse sessions, even though they did not smoke. Any effect that the lapse sessions may have had on the likelihood of smoking cannot be determined in the present study due to the absence of a 14C condition with participants who did not attend lapse sessions. Indeed, in one of the two studies of which we are aware that showed an increase in relapse risk associated with exposure to programmed lapses (five cigarettes in 4 hr), denicotinized cigarettes were just as effective at increasing the likelihood of smoking as standard cigarettes (Juliano, Donny, Houtsmuller, & Stitzer, 2006
). The failure to find differences between nicotinized and denicotinized cigarettes suggests strongly that the stimulus factors of smoking (e.g., sight and feel of cigarette, smell and taste of smoke) are important to any effect of programmed lapses on the probability of future smoking. Worth mentioning is that participants in the Juliano et al. study also received monetary incentives to sustain abstinence, but at a daily magnitude that was only approximately one fourth or less of that used in the present study. Also, magnitude was reduced over time, rather than increased as in the present study, in order to increase the likelihood that participants would smoke.
In the one other study in which programmed lapses increased subsequent smoking, there were no programmed monetary incentives for sustaining abstinence, and participants were not trying to quit smoking long term, suggesting little immediate naturalistic reinforcement for sustaining abstinence following exposure to the programmed lapses (Chornock, Stitzer, Gross, & Leischow, 1992
). Considering results across the present and the two earlier studies, the effects of lapses on the future probability of resuming smoking appear likely to depend on whether and at what amount reinforcement for sustaining abstinence is available.
Results from the participant rating scales in the present study failed to show any effects of programmed lapses, but otherwise replicated previous findings from our laboratory showing dynamic changes in the 14C conditions compared to the 1C condition during the initial 2 weeks of abstinence that are consistent with a lowering of relapse risk (Alessi et al., 2004
; Lussier et al., 2005
). The most consistent observation across the present and prior studies is that participants rated the challenge of abstaining from smoking as progressively easier as the duration of abstinence increased. As noted previously (Lussier et al.), lower response effort has been demonstrated in basic and applied research to increase the probability of responding (Friman & Poling, 1995
). To the extent that abstaining from smoking can be considered an operant response or task (which we believe is clearly supported by the present results), a history of successfully abstaining coupled with a progressive increase in the perceived ease of abstaining could reasonably be expected to be associated with an increase in the probability of sustaining abstinence in the future. In population surveys of current smokers, perceived difficulty associated with quitting appears to deter smokers from attempting to quit (Mullins & Borland, 1996
). In addition to observing increases in self-reported ease of abstaining, the current study replicates previous findings indicating that ratings of confidence in abstaining tomorrow increase with increasing abstinence, and withdrawal and craving peak in the initial days of abstinence and then decrease over the course of a 2-week period of sustained abstinence. Any or all of these dynamic changes during the first 2 weeks of abstinence might conceivably facilitate longer term abstinence.
Overall, the present study provided further evidence that supports the effectiveness of contingency management interventions to exert robust control over cigarette smoking in the natural environment, while also illustrating further their utility as a research tool in addition to a treatment intervention. Results on the influence of programmed smoking lapses revealed no disruptive influence while reinforcement magnitude for sustaining abstinence was relatively high (e.g., $3.00 to $10.00 per session for abstinence during abstinence monitoring) but at least limited disruption when the magnitude was lower (e.g., $0.25 per choice during the smoking preference sessions). Results also support those from prior studies suggesting that a period of sustained abstinence during the initial weeks of abstinence results in changes that likely lower relapse risk.