Transient compensatory smoking in response to placebo cigarettes

Rationale

To address the public health problems caused by smoking, researchers have suggested a gradual reduction in the nicotine content of cigarettes. There remain concerns, however, about the potential for smokers to compensate for reductions in nicotine content by altering their smoking behavior. Such compensatory behaviors may negate any potential cessation and/or harm reduction benefits.

Objective

The purpose of this study was to quantify smoking behavior (e.g., puff number, volume, duration, interpuff interval, and peak flow) in response to cigarettes, varying only in nicotine content, administered repeatedly.

Methods

Sixty-seven dependent smokers participated in this two-session, within-subject study. Moderate nicotine content and placebo cigarettes (Quest© brand) were administered in a double-blind and counterbalanced manner. Each session required 12 h of tobacco abstinence and included four ad lib smoking bouts of the condition-assigned cigarette with 40 minutes separating each bout.

Results

Placebo cigarettes produced increases in total puff volume and duration and decreases in total interpuff interval relative to cigarettes with moderate nicotine content. Differences in total puff volume and duration generally dissipated across smoking bouts, with differences in total puff volume nonexistent by the third and fourth bouts.

Conclusions

Placebo cigarettes produce compensatory smoking during initial exposures; however, these effects appear to be short lived. These findings are consistent with the previous work where smoking compensation has been observed in response to a single cigarette, but not over several days of smoking.     

Modeling the effect of alcohol on smoking lapse behavior

Objective

The primary aim of this project was to examine the role of alcohol use in smoking lapse behavior, as alcohol consumption is a known risk factor for poor smoking cessation outcomes.

Materials and methods

We have developed a novel human laboratory model to examine two primary aspects of alcohol-mediated tobacco relapse: (1) Does alcohol facilitate the initiation of the first cigarette? (2) Once the first cigarette is initiated, does alcohol facilitate subsequent smoking? Using a within-subject design, 16 daily smokers who were also heavy social drinkers received a priming drink (0.03 g/dl or taste-masked placebo) and then had the option of initiating a tobacco self-administration session or delaying initiation by 5-min increments for up to 50 min in exchange for monetary reinforcement. Subsequently, the tobacco self-administration session consisted of a 1-h period in which subjects could choose to smoke their preferred brand of cigarettes using a smoking topography system or receive monetary reinforcement for cigarettes not smoked. Alcohol craving, tobacco craving, subjective reactivity to alcohol, and nicotine withdrawal were assessed as secondary outcomes.

Results

Results demonstrated that after consuming the alcohol beverage, subjects were less able to resist the first cigarette and initiated their smoking sessions sooner, and smoked more cigarettes compared to the placebo beverage. These findings have implications for smoking cessation in alcohol drinkers and model development to assess smoking lapse behavior.     

Varenicline,low dose naltrexone,and their combination for heavy-drinking smokers: human laboratory findings

Rationale

Heavy-drinking smokers constitute a sizeable and hard-to-treat subgroup of smokers, for whom tailored smoking cessation therapies are not yet available.

Objectives

The present study used a double-blind, randomized, 2?×?2 medication design, testing varenicline alone (VAR; 1 mg twice daily), low dose naltrexone alone (L-NTX; 25 mg once daily), varenicline plus naltrexone, and placebo for effects on cigarette craving and subjective response to alcohol and cigarettes in a sample (n?=?130) of heavy-drinking daily smokers (≥10 cigarettes/day).

Methods

All participants were tested after a 9-day titration period designed to reach a steady state on the target medication. Testing was completed at 12 h of nicotine abstinence, after consuming a standard dose of alcohol (target breath alcohol concentration?=?0.06 g/dl) and after smoking the first cigarette of the day.

Results

The combination of VAR?+?L-NTX was superior to placebo, and at times superior to monotherapy, in attenuating cigarette craving, cigarette and alcohol “high,” and in reducing ad-lib consumption of both cigarettes and alcohol during the 9-day medication titration period.

Conclusions

These preliminary findings indicate that clinical studies of the combination of VAR?+?L-NTX for heavy drinkers trying to quit smoking are warranted and may ultimately improve clinical care for this sizeable and treatment-resistant subgroup of smokers.     

Acute electronic cigarette use: nicotine delivery and subjective effects in regular users

Rationale

Electronic cigarettes are becoming increasingly popular among smokers worldwide. Commonly reported reasons for use include the following: to quit smoking, to avoid relapse, to reduce urge to smoke, or as a perceived lower-risk alternative to smoking. Few studies, however, have explored whether electronic cigarettes (e-cigarettes) deliver measurable levels of nicotine to the blood.

Objective

This study aims to explore in experienced users the effect of using an 18-mg/ml nicotine first-generation e-cigarette on blood nicotine, tobacco withdrawal symptoms, and urge to smoke.

Methods

Fourteen regular e-cigarette users (three females), who are abstinent from smoking and e-cigarette use for 12 h, each completed a 2.5 h testing session. Blood was sampled, and questionnaires were completed (tobacco-related withdrawal symptoms, urge to smoke, positive and negative subjective effects) at four stages: baseline, 10 puffs, 60 min of ad lib use and a 60-min rest period.

Results

Complete sets of blood were obtained from seven participants. Plasma nicotine concentration rose significantly from a mean of 0.74 ng/ml at baseline to 6.77 ng/ml 10 min after 10 puffs, reaching a mean maximum of 13.91 ng/ml by the end of the ad lib puffing period. Tobacco-related withdrawal symptoms and urge to smoke were significantly reduced; direct positive effects were strongly endorsed, and there was very low reporting of adverse effects.

Conclusions

These findings demonstrate reliable blood nicotine delivery after the acute use of this brand/model of e-cigarette in a sample of regular users. Future studies might usefully quantify nicotine delivery in relation to inhalation technique and the relationship with successful smoking cessation/harm reduction.     

A selective reversible monoamine oxidase B inhibitor in smoking cessation: effects on its own and in association with transdermal nicotine patch

Rationale

Monoamine oxidase B (MAO-B) activity is reduced in smokers. A MAO-B inhibitor alone or co-administered with nicotine may mimic the effects of smoking and be a candidate drug for smoking cessation.

Objective

This study aims to determine the efficacy and safety of EVT302, a selective reversible MAO-B inhibitor, alone and on top of nicotine patch (NP) in smoking cessation.

Methods

This was a randomised, double blind, placebo-controlled phase II, multicentre trial. Smokers (≥10 cigarettes/day) received either EVT302 (N?=?145) or placebo (N?=?145), or EVT302 (N?=?61) or placebo (N?=?61) on top of open label NP 21 mg/day for 8 weeks. The main comparison was between EVT302 and placebo without NP. The primary outcome measure was end-of-treatment 4-week continuous abstinence rate (CAR). Secondary outcome measures: point prevalence abstinence rate, saliva cotinine concentrations in the groups without NP, urge to smoke, nicotine withdrawal symptoms and assessment of subjective effects of cigarettes.

Results

The 4-week CAR was 15.2 % in the placebo, 17.2 % in the EVT302, 26.8 % in the NP?+?placebo and 32.8 % in the NP?+?EVT302 groups, respectively. There was no difference between EVT302 and placebo either alone (adjusted OR: 1.45, 95 % CI: 0.65–3.26) or when co-administered with NP. No statistically significant difference occurred for the secondary outcome measures.

Conclusions

The selective, reversible MAO-B inhibitor EVT302 was not superior to placebo in helping smokers quit, in line with data with selegiline and confirms that MAO-B inhibitors are not effective in smoking cessation. Co-administration of NP does not provide a supplementary benefit.     

Thalamic glutamate decreases with cigarette smoking

Rationale

Findings from animal studies and human PET imaging indicate that nicotine and cigarette smoking affect glutamate (Glu) and related neurochemical markers in the brain and imply that smoking reduces extracellular Glu. As Glu release is mediated by nicotinic acetylcholine receptors (nAChRs), which are present at high concentrations in the thalamus, we examined the effects of smoking on thalamic Glu.

Objective

To determine the effects of tobacco smoking on thalamic glutamate levels.

Methods

Thalamic Glu levels were measured in vivo in 18 smokers and 16 nonsmokers using proton magnetic resonance spectroscopic imaging (¹H MRSI) at 1.5 T.

Results

Mean Glu levels did not differ significantly between the subject groups. However, within smokers, Glu levels were negatively correlated with self-reports of both cigarettes/day over the last 30 days (r?=??0.64, p?=?0.006) and pack-years of smoking (r?=??0.66, p?=?0.005).

Conclusions

Consistent with expectations based on preclinical studies, within smokers, cigarettes/day and pack-years are associated with reduced Glu in thalamus, a brain region rich in nAchRs. These results encourage work on candidate glutamatergic therapies for smoking cessation and suggest a noninvasive metric for their action in the brain.     

Acute effects of low and high dose alcohol on smoking lapse behavior in a laboratory analogue task

Rationale

Smoking lapses (i.e., returns to smoking after quitting) often occur following alcohol consumption with observational data suggesting greater quantities of alcohol lead to greater risk. However, a causal dose-dependent effect of alcohol consumption on smoking lapse behavior has not been established, and the mechanisms that might account for such an effect have not been tested.

Objectives

In a within-subjects design, we examined the effects of low- (0.4 g/kg) and high-dose (0.8 g/kg) alcohol, relative to placebo, on smokers’ ability to resist initiating smoking after acute smoking abstinence.

Methods

Participants were 100 heavy alcohol drinkers, smoking 10–30 cigarettes per day. Across three separate days, participants consumed placebo, low-dose, or high-dose alcohol following 3 h of smoking abstinence and, 35 min later, were offered the opportunity to smoke while resisting smoking was monetarily reinforced proportional to the amount of time delayed.

Results

Consistent with a dose–response effect, participants smoked 3.35 min (95 % confidence intervals (CI) [?7.09, 0.40], p?=?.08) earlier following low-dose alcohol and 6.36 min (95 % CI [?9.99, ?2.73], p?=?.0006) earlier following high-dose alcohol compared to drinking a placebo beverage. Effects of dose on smoking behavior were partially mediated by increases in urge to smoke. There was no evidence that alcohol’s effects on urge to smoke or ability to resist smoking were mediated through its stimulating or sedating effects.

Conclusions

Alcohol can reduce the ability to resist smoking in a dose-dependent fashion, in part, due to its effect on increasing the intensity of smoking urges.     

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

Rationale

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.

Objective

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.

Methods

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.

Results

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.

Conclusions

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.     

Varenicline versus transdermal nicotine patch: a 3-year follow-up in a smoking cessation clinic in Taiwan

Rationale

A network meta-analysis of randomized trials and real-world comparative studies strongly suggest that varenicline is more effective in aiding smoking cessation than single form nicotine replacement therapy (NRT). Modeling the health benefits attributable to this difference relies on extrapolation to lifetime cessation, but to date, follow-up has only extended to 12 months. Longer term follow-up data are helpful in checking these assumptions.

Objectives

This study aimed to compare the sustained abstinence rates of smokers using varenicline versus nicotine patch in their quit attempt up to 36 months.

Method

Five hundred eighty-seven smokers were recruited at Kaohsiung Veteran General Hospital between Feb 2006 and Aug 2009. Participants received counseling from a physician and received either varenicline (N?=?296) or the nicotine patch (N?=?291) for smoking cessation. Both varenicline and nicotine patch users could receive their medications for a maximum of 8 weeks. Participants were followed up by telephone at 3, 6, 12, and 36 months from the first visit. The primary outcome measure was self-reported sustained abstinence up to 36 months. Measures were also taken of smoking characteristics, cigarette dependence, and sociodemographic characteristics.

Results

Multiple logistic regression of 36-month sustained abstinence on to medication adjusting for other baseline variables showed a significant advantage for varenicline, OR?=?7.94 (95 % CI 1.87–33.74).

Conclusion

An 8-week course of varenicline appears to yield higher abstinence rate up to 3 years than a similar length course of nicotine transdermal patch in routine clinical practice where behavioral support is available.     

Reinforcement enhancing effects of nicotine via smoking

Rationale

In animals, nicotine enhances reinforcement from stimuli unrelated to nicotine intake. Human research is suggestive but has not clearly shown a similar influence of nicotine.

Objectives

We assessed acute effects of nicotine via smoking on enhancement of positive (money, music) or negative (termination of noise) reinforcers, or no “reward” (control). These different rewards determined the generalizability of nicotine effects.

Materials and methods

Dependent (n?=?25) and nondependent (n?=?27) smokers participated in three sessions, each after overnight abstinence. Using a within-subjects design, sessions involved no smoking or smoking denicotinized (0.05 mg) or nicotine (0.6 mg) Quest^R brand cigarettes. For comparison, a fourth session involved no abstinence prior to smoking one's own brand to gauge responses under typical nicotine satiation. Reinforcement was assessed by responses on a simple operant computer task for the rewards, each available singly on a progressive ratio schedule during separate trials.

Results

The reinforcing effect of music, but not other rewards, was greater due to the nicotine cigarette, compared to the denicotinized cigarette or no smoking. Reinforcement enhancing effects of nicotine did not differ between dependent and nondependent groups, indicating no influence of withdrawal relief. Responding due to acute nicotine after abstinence was very similar to responding to one's own brand after no abstinence.

Conclusions

Acute nicotine intake per se from smoking after abstinence enhances the reinforcing value of rewards unassociated with smoking, perhaps in a manner comparable to ad lib smoking after no abstinence. Nicotine's reinforcement enhancing effects may be specific to certain rewards, perhaps those sensory in nature.     

The effects of extended intravenous nicotine administration on body weight and meal patterns in male Sprague–Dawley Rats

Rationale

Increased appetite and weight gain after cessation is a deterrent for quitting smoking. Attempts to understand the mechanism for these effects using animals have been hampered by the difficulty or inconsistency of modeling the effects seen in humans.

Objective

To examine the effects of extended daily access to intravenous nicotine, via programmed infusions, on body weight and meal patterns in rats.

Methods

Intravenous (IV) nicotine infusions (0.06 mg/kg/inf) were administered noncontingently, every 30 min throughout the dark cycle and the last 3 h of the light cycle, to emulate self-administration. The effect of these infusions on food intake, meal patterns, and weight change were examined relative to a control group during treatment and in a post-nicotine phase.

Results

Nicotine-treated rats gained half the weight that vehicle treated animals gained and ate approximately 20 % less food overall than vehicle-treated rats. Whereas a compensatory increase in meal frequency occurred during the dark period to account for smaller meals, no compensation was observed throughout the light period. In a post-nicotine phase, the nicotine group maintained a lower weight for 1 week and then gained weight back to control levels. The rate of weight gain post-cessation was faster in animals that had received nicotine compared to controls.

Conclusion

Compared to previous studies examining the effects of minipump or intraperitoneal injections of nicotine on food intake, the present study was able to detect previously unknown circadian differences in meal patterns which will be important in the development of smoking cessation and weight gain prevention drugs.     

The effects of varenicline on attention and inhibitory control among treatment-seeking smokers

Rationale

Varenicline represents a new class of smoking cessation aids that has different mechanisms of action that are unique from bupropion or nicotine replacement therapies. An improved understanding of these mechanisms may lead to greater treatment success in quitting smoking.

Objectives

We examined the effects of steady-state varenicline on attention and inhibitory control among adult treatment-seeking smokers.

Methods

Adult smokers enrolled in a randomized clinical trial received either 4 weeks of pre-quit varenicline (n?=?31) or 3 weeks of placebo (n?=?26) followed by 1 week of standard varenicline treatment. Participants in the present work completed cognitive assessments at a baseline session (prior to treatment) and again 3 weeks later (during active treatment). At both sessions, participants completed the stop signal task to assess both lapses in attention and inhibitory control.

Results

Analyses indicated that varenicline improved lapses in attention compared to placebo. There were no significant differences observed between groups at either session for inhibitory control.

Conclusions

The present study demonstrated that varenicline improves lapses in attention among treatment-seeking smokers preparing to make a quit attempt. These findings suggest that the domain of attention may be a good candidate for larger studies of the role of improved cognition in understanding the mechanisms of varenicline treatment for smoking cessation.     

The relationship between the nicotine metabolite ratio and three self-report measures of nicotine dependence across sex and race

Rationale

Variability in the rate of nicotine metabolism, measured by the nicotine metabolite ratio (NMR), is associated with smoking behavior. However, data linking the NMR with nicotine dependence measured by the Fagerström test for nicotine dependence (FTND) are mixed. Few past studies have examined alternative measures of nicotine dependence and how this relationship may vary by sex and race.

Objective

Using data from smokers undergoing eligibility evaluation for a smoking cessation clinical trial (n?=?833), this study examined variability in the relationship between NMR and nicotine dependence across sex and race and using three measures of nicotine dependence: FTND, time-to-first-cigarette (TTFC), and the heaviness of smoking index (HSI).

Results

Controlling for sex and race, nicotine metabolism was associated with nicotine dependence only when using the HSI (p?<?0.05). Male normal metabolizers of nicotine were more likely to have high nicotine dependence based on the FTND and HSI (p?<?0.05), but NMR was not related to measures of nicotine dependence in women. For African Americans, the NMR was associated with nicotine dependence only for the TTFC (p?<?0.05), but NMR was not associated with nicotine dependence among Caucasians. Post hoc analyses indicated that the NMR was associated with cigarettes per day, overall, and among men and Caucasians (p?<?0.05).

Conclusions

While there was some variation in the relationship between nicotine metabolism and nicotine dependence across measures and sex and race, the results indicate that this relationship may be more attributable to the association between NMR and cigarettes per day.     

Measuring smoking-related preoccupation and compulsive drive: evaluation of the obsessive compulsive smoking scale

Rationale

Tobacco use for many people is compulsive in nature. Compelling theories of how smoking becomes compulsive exist but are largely based on extrapolation from neuroscience findings. Research on smokers is impeded, in part, by a lack of instruments that specifically measure compulsive smoking.

Objective

This study evaluated the measurement structure and validity of the Obsessive Compulsive Smoking Scale (OCSS), a ten-item questionnaire designed to measure compulsive smoking.

Methods

Participants were 239 daily smokers (≥1 cigarette/day), including 142 students at a public university in Chicago and 97 veterans treated at the VA Boston Healthcare System. The OCSS and questionnaires measuring current and past smoking, cigarette craving, automatic smoking, and nicotine dependence were administered.

Results

Factor analysis with maximum likelihood extraction and oblique rotation revealed two correlated underlying factors, interpreted as “Preoccupation with Smoking” and “Compulsive Drive.” The measurement structure was consistent across students and veterans, and confirmed in an independent sample of adults (n?=?95). Veterans exhibited higher OCSS scores (full scale and subscales) than students. Across groups, higher OCSS scores were positively correlated with smoking intensity, craving, and nicotine dependence. OCSS full-scale and compulsive drive scores, but not smoking preoccupation scores, were inversely correlated with past month smoking reduction and minutes since last cigarette.

Conclusions

The OCSS is a valid and reliable inventory for measuring the degree to which daily smokers are preoccupied with smoking and engage in compulsive tobacco use, and may be useful for advancing understanding of core smoking phenotypes or for tailoring cessation therapies.     

Urge to smoke over 52 weeks of abstinence

Rationale

Cigarette cravings are well documented during the first weeks of smoking abstinence. Treatments focus on helping smokers reduce these acute cravings. Cravings experienced later on are less well understood and may be important when considering treatment duration.

Objective

We conducted a longitudinal study of cravings over 52 weeks of smoking abstinence.

Methods

Cravings were operationalised as strength of, and time spent with, urges to smoke. These were assessed among 452 smokers quitting with behavioural support but without pharmacotherapies. Individuals maintaining abstinence were assessed at 1, 2, 3, 4, 26 and 52 weeks after quitting (n?=?197, 156, 139, 131, 66 and 38, respectively). Abstinence was validated at each assessment by expired carbon monoxide. Time courses were plotted for those abstinent for 52 weeks and for those abstinent up to earlier time points. Correlations were examined between ratings of urges at consecutive time points.

Results

Ratings of strength of urges to smoke followed an exponential decline over 52 weeks of abstinence, but 6 months after quitting 13 % of ex-smokers still reported strong urges. At 12 months, no ex-smokers reported strong urges, although 34 % reported some urges. Strength of urges to smoke after 1, 2, 3 and 4 weeks of abstinence predicted strength of urges at 6 months.

Conclusions

Strength of urges to smoke decline exponentially over time following smoking cessation, though some smokers report strong urges after 6 months of abstinence, and urges are still reported by a third of smokers after 12 months. Relapse prevention treatments may need to target prolonged craving.     

An exploratory examination of the mechanisms through which pre-quit patch use aids smoking cessation

Rationale and objectives

Patches are traditionally started on the day a quit attempt begins. Recently, a number of studies have established that the patch’s effectiveness is improved by starting the treatment before quitting [pre-quit patch (PQP) use]. In an exploratory study, we investigate a proposed mechanism through which PQP use might promote abstinence: that PQP reduces satisfaction with smoking (either directly or via craving), which in turn leads to reduction and that smoking reduction promotes abstinence.

Methods

Fifty-seven interested quitters used handheld computers to monitor their smoking satisfaction, withdrawal and smoking in real time for 17 days, leading up to a quit attempt. All participants received 21 mg/24 h patches for 2 weeks before and for up to 10 weeks after quitting. Carbon dioxide (CO)-verified 28-day abstinence was assessed.

Results

During PQP treatment, participants reported significant reductions in both the satisfaction gained from smoking (p?<?0.001) and their daily cigarette consumption (p?<?0.001). Craving did not decrease; however, there was an interaction between time and nicotine dependence; craving decreased only among low dependent participants. Multilevel structural equation modelling revealed a direct effect of satisfaction on smoking rate. Craving did not mediate this relationship. Smoking reduction during the PQP treatment phase was not significantly associated with abstinence.

Conclusions

The real-time data collection protocol utilised allowed for a fine-grained examination of smoking during PQP treatment. The results suggest that the reduction in daily cigarette smoking typically observed during PQP treatment is due to reductions in satisfaction with smoking. Unlike previous studies, however, smoking reduction was not significantly related to later abstinence, even though the odds ratio was comparably. Potential clinical implications of these findings are discussed.     

Effect of high-dose nicotine patch on craving and negative affect leading up to lapse episodes

Rationale

Nicotine patches have been reliably demonstrated to improve smoking cessation outcomes but most users still lapse, and then relapse, during treatment. While patch has been shown to alleviate background cravings, its effects on cue-induced cravings — which have been linked to the occurrence of lapse events — are poorly understood.

Objectives

Here we investigate the effect of nicotine patch on the intensity of craving and negative affect experienced during the hours immediately preceding lapse episodes.

Methods

Participants were 185 smokers who had quit in the context of a randomized, double-blind trial of high-dose (35 mg) nicotine patch and who lapsed at least once during the first 5 weeks of treatment. Participants used electronic diaries to monitor their smoking, affect, and craving during their cessation attempt.

Results and conclusions

The data suggest that developments on the lapse day — either external events or changes in internal states — caused craving and negative affect to rise, cumulating in the lapse. Nicotine is known to lower background craving and negative affect, but the difference between patch and placebo appeared to dissipate in the hours immediately preceding lapse episodes. Understanding the process by which these symptoms "spike" prior to a lapse — and developing treatments to counter it — are worthy research endeavors.     

Predictors of smoking lapse in a human laboratory paradigm

Rationale

During a smoking quit attempt, a single smoking lapse is highly predictive of future relapse. While several risk factors for a smoking lapse have been identified during clinical trials, a laboratory model of lapse was until recently unavailable and, therefore, it is unclear whether these characteristics also convey risk for lapse in a laboratory environment.

Objectives

The primary study goal was to examine whether real-world risk factors of lapse are also predictive of smoking behavior in a laboratory model of smoking lapse.

Methods

After overnight abstinence, 77 smokers completed the McKee smoking lapse task, in which they were presented with the choice of smoking or delaying in exchange for monetary reinforcement. Primary outcome measures were the latency to initiate smoking behavior and the number of cigarettes smoked during the lapse. Several baseline measures of smoking behavior, mood, and individual traits were examined as predictive factors.

Results

Craving to relieve the discomfort of withdrawal, withdrawal severity, and tension level were negatively predictive of latency to smoke. In contrast, average number of cigarettes smoked per day, withdrawal severity, level of nicotine dependence, craving for the positive effects of smoking, and craving to relieve the discomfort of withdrawal were positively predictive of number of cigarettes smoked.

Conclusions

The results suggest that real-world risk factors for smoking lapse are also predictive of smoking behavior in a laboratory model of lapse. Future studies using the McKee lapse task should account for between subject differences in the unique factors that independently predict each outcome measure.     

Sex differences in stimulus expectancy and pharmacologic effects of a moderate dose of alcohol on smoking lapse risk in a laboratory analogue study

Rationale

Alcohol use is often implicated in initial lapses to smoking during quit smoking attempts. Mechanisms explaining this association are unknown but could include (a) learned associations between drinking and smoking or (b) direct pharmacologic effects of alcohol.

Objectives

In a 2 (told alcohol vs. told placebo)?×?2 (0.4?g/kg vs. 0.0?g/kg ethanol) between-subjects balanced placebo design, we examined instruction and beverage condition effects on smokers?? ability to resist initiating smoking and whether these effects differed by sex.

Methods

Participants were 96 heavy alcohol drinkers, smoking 10?C30 cigarettes per day. After 15?h of smoking abstinence, participants consumed either an alcoholic or a nonalcoholic beverage and 35?min later completed a smoking lapse task.

Results

Overall, neither instructions nor beverage contents influenced behavior on the smoking lapse task. However, the instruction condition had different effects in men and women. Women, but not men, were more likely to smoke and reported expecting greater satisfaction from smoking when they were told alcohol compared to told placebo. The effects of instruction condition on smoking behavior were not mediated by self-reported expected satisfaction from smoking.

Conclusions

Women may be more likely to choose to smoke after drinking moderate amounts of alcohol because of their expectations rather than the pharmacological effects of the alcohol.     

Methylphenidate increases cigarette smoking in participants with ADHD

Rationale

Methylphenidate (Ritalin®) is commonly prescribed for behavioral problems associated with attention deficit/hyperactivity disorder (ADHD). The results of previous studies suggest that methylphenidate increases cigarette smoking in participants without psychiatric diagnoses. Whether methylphenidate increases cigarette smoking in participants diagnosed with ADHD is unknown.

Objective

In this within-subjects, repeated measures experiment, the acute effects of a range of doses of methylphenidate (10, 20, and 40 mg) and placebo were assessed in nine cigarette smokers who were not attempting to quit and met diagnostic criteria for ADHD but no other Axis I psychiatric disorders other than nicotine dependence.

Methods

Each dose of methylphenidate was tested once while placebo was tested twice. One hour after ingesting drug, participants were allowed to smoke ad libitum for 4 h. Measures of smoking included total cigarettes smoked, total puffs, and carbon monoxide levels. Snacks and decaffeinated drinks were available ad libitum; caloric intake during the 4-h smoking session was calculated.

Results

Methylphenidate increased the total number of cigarettes smoked, total number of puffs, and carbon monoxide levels. Methylphenidate decreased the number of food items consumed and caloric intake.

Conclusions

The results of this experiment suggest that acutely administered methylphenidate increases cigarette smoking in participants with ADHD, which is concordant with findings from previous studies that tested healthy young adults. These data indicate that clinicians may need to consider non-stimulant options or counsel their patients before starting methylphenidate when managing ADHD-diagnosed individuals who smoke.