Prequit fMRI responses to pleasant cues and cigarette-related cues predict smoking cessation outcome.
ABSTRACT: The reasons that some smokers find it harder to quit than others are unclear. Understanding how individual differences predict smoking cessation outcomes may allow the development of more successful personalized treatments for nicotine dependence. Theoretical models suggest that drug users might be characterized by increased sensitivity to drug cues and by reduced sensitivity to nondrug-related natural rewards. We hypothesized that baseline differences in brain sensitivity to natural rewards and cigarette-related cues would predict the outcome of a smoking cessation attempt.Using functional magnetic resonance imaging, we recorded prequit brain responses to neutral, emotional (pleasant and unpleasant), and cigarette-related cues from 55 smokers interested in quitting. We then assessed smoking abstinence, mood, and nicotine withdrawal symptoms during the course of a smoking cessation attempt.Using cluster analysis, we identified 2 groups of smokers who differed in their baseline responses to pleasant cues and cigarette-related cues in the posterior visual association areas, the dorsal striatum, and the medial and dorsolateral prefrontal cortex. Smokers who showed lower prequit levels of brain reactivity to pleasant stimuli than to cigarette-related cues were less likely to be abstinent 6 months after their quit attempt, and they had higher levels of negative affect during the course of the quit attempt.Smokers with blunted brain responses to pleasant stimuli, relative to cigarette-related stimuli, had more difficulty quitting smoking. For these individuals, the lack of alternative forms of reinforcement when nicotine deprived might be an important factor underlying relapse. Normalizing these pathological neuroadaptations may help them achieve abstinence.
Project description:BACKGROUND:Understanding how smoking cessation treatments exert their effects can inform treatment development and use. Factorial designs allow researchers to examine whether multiple intervention components affect hypothesized change mechanisms, and whether the affected mechanisms are related to cessation. METHODS:This is a secondary data analysis of smokers recruited during primary care visits (N=637, 55% women, 87% white) who were motivated to quit. Participants in this fractional factorial experiment were randomized to one level of each of six intervention factors: Prequit Nicotine Patch vs None, Prequit Nicotine Gum vs None, Preparation Counseling vs None, Intensive In-Person Counseling vs Minimal, Intensive Phone Counseling vs Minimal, and 16 vs 8 Weeks of Combination Nicotine Replacement (nicotine patch+nicotine gum). Data on putative mechanisms (e.g., medication use, withdrawal, self-efficacy) and smoking status were gathered using daily assessments and during follow-up assessment calls. RESULTS:Some intervention components influenced hypothesized mechanisms. Prequit Gum and Patch each reduced prequit smoking and enhanced prequit coping and self-efficacy. In-Person Counseling increased prequit motivation to quit, postquit self-efficacy, and postquit perceived intratreatment support. Withdrawal reduction and reduced prequit smoking produced the strongest effects on cessation. The significant effect of combining Prequit Gum and In-Person Counseling on 26-week abstinence was mediated by increased prequit self-efficacy. CONCLUSIONS:This factorial experiment identified which putative treatment mechanisms were influenced by discrete intervention components and which mechanisms influenced cessation. Such information supports the combined use of prequit nicotine gum and intensive in-person counseling as cessation interventions that operate via increased prequit self-efficacy.
Project description:The present investigation examined whether anxiety sensitivity, relative to anxiety and depressive symptoms, was related to duration to early smoking lapse and relapse (during first 2 weeks postquit) among daily smokers receiving smoking cessation treatment.Participants included 123 daily cigarette smokers (84 women; M(age) = 45.93 years, SD = 10.34) living in the Halifax Regional Municipality in Nova Scotia, Canada.Anxiety sensitivity was significantly associated with an increased risk of early smoking lapse (i.e., any smoking behavior) at days 1, 7, and 14 following the quit day. Such effects were evident above and beyond the variance accounted for by gender, nicotine dependence, and nicotine withdrawal symptoms, as well as the shared variance with prequit (baseline) anxiety and depressive symptoms. In contrast to expectation, anxiety sensitivity was not related to smoking relapse (i.e., seven consecutive days of smoking) during the first 2 weeks of quitting.Results are discussed in terms of better understanding the role of anxiety sensitivity, along with other affective vulnerability processes, in early problems encountered during a quit attempt.
Project description:This study replicated and extended results of a previous trial, which found that combination varenicline/bupropion treatment increased smoking abstinence in smokers who were male, highly dependent, and who did not respond to prequit nicotine patch treatment with a >50% reduction in expired-air carbon monoxide in the first week.One hundred and twenty-two male nicotine patch nonresponders and 52 responders were identified. Smokers in each group were randomized to receive 12 weeks of varenicline plus bupropion treatment versus varenicline plus placebo. The primary outcome was continuous smoking abstinence at weeks 8-11 after the target quit date.For smokers with a high level of dependence, judged by having a baseline Fagerstrom Test for Nicotine Dependence (FTND) score ? 6 and cigarette consumption ? 20/d, combination varenicline/bupropion treatment increased the abstinence rate relative to varenicline alone: 71.0% versus 43.8% (odds ratio = 3.14; 95% confidence interval = 1.11-8.92, p [one tailed] = .016). In contrast, less dependent smokers did not show a benefit of combination treatment relative to varenicline (abstinence rates of 32.1% vs. 45.6%, respectively); there was a significant interaction of treatment and dependence level. Patch nonresponders tended to benefit the most from combination treatment, which was well tolerated overall.Combination varenicline/bupropion treatment proved significantly more efficacious than varenicline alone among highly dependent male smokers. These results, together with prior studies, support an adaptive treatment paradigm that assigns smoking cessation treatment according to baseline smoker characteristics and initial response to nicotine patch treatment.This study replicated, in a prospective manner, an important and surprising retrospective finding from a previous clinical trial, which showed that a specific subpopulation of smokers benefited substantially from receiving a combination treatment of varenicline plus bupropion, relative to varenicline plus placebo. Specifically, male smokers having high baseline nicotine dependence (FTND score ? 6 and cigarette consumption ? 20/d), showed a marked increase in smoking abstinence rate on combination pharmacotherapy. The present study likewise found an enhancement in end-of-treatment abstinence rate in this subgroup, from 43.8% to 71.0%. The adaptive treatment paradigm, which classifies smokers based on initial dependence level and response to prequit nicotine patch treatment, may be used to identify target populations of smokers whose success can be enhanced by intervening with combination pharmacotherapy before the quit-smoking date.ClinicalTrials.gov identifier: NCT01806779.
Project description:Developing the means to identify smokers at high risk for relapse could advance relapse prevention therapy. We hypothesized that functional magnetic resonance imaging (fMRI) reactivity to smoking-related cues, measured before a quit attempt, could identify smokers with heightened relapse vulnerability.Before quitting smoking, 21 nicotine-dependent women underwent fMRI during which smoking-related and neutral images were shown. These smokers also were tested for possible attentional biases to smoking-related words using a computerized emotional Stroop (ES) task previously found to predict relapse. Smokers then made a quit attempt and were grouped based on outcomes (abstinence vs. slip: smoking > or = 1 cigarette after attaining abstinence). Prequit fMRI and ES measurements in these groups were compared.Slip subjects had heightened fMRI reactivity to smoking-related images in brain regions implicated in emotion, interoceptive awareness, and motor planning and execution. Insula and dorsal anterior cingulate cortex (dACC) reactivity induced by smoking images correlated with an attentional bias to smoking-related words. A discriminant analysis of ES and fMRI data predicted outcomes with 79% accuracy. Additionally, smokers who slipped had decreased fMRI functional connectivity between an insula-containing network and brain regions involved in cognitive control, including the dACC and dorsal lateral prefrontal cortex, possibly reflecting reduced top-down control of cue-induced emotions.These findings suggest that the insula and dACC are important substrates of smoking relapse vulnerability. The data also suggest that relapse-vulnerable smokers can be identified before quit attempts, which could enable personalized treatment, improve tobacco-dependence treatment outcomes, and reduce smoking-related morbidity and mortality.
Project description:Worldwide, approximately one billion people smoke cigarettes. Cigarette smoking persists in part because long-term smoking cessation rates are modest on existing treatments. Smoking cessation outcomes are influenced by genetic factors, including genetic variation in enzymes that metabolize nicotine and smoking cessation medications, as well as in receptor targets for nicotine and treatment medications. For example, smokers with genetically slow nicotine metabolism have higher cessation success on behavioural counseling and nicotine patches compared with smokers with genetically fast nicotine metabolism. In this review, we highlight new progress in our understanding of how genetic variation in the pharmacological targets of nicotine and smoking cessation medications could be used to tailor smoking cessation therapy, increase quit rates, and reduce tobacco-related harm.
Project description:Many smokers reported using Electronic Nicotine Delivery System (ENDS, e.g., electronic cigarettes or e-cigarettes) to quit cigarette smoking. Previous studies suggested that daily ENDS use may promote cigarette smoking cessation. We assessed variations in the prevalence of daily ENDS use among adult smokers by demographics and implications for cigarette smoking disparities. Data were from a nationally representative sample of US adults who participated in the 2014-2015 Tobacco Use Supplement to the Current Population Survey (n = 163,920). Participants reported socio-demographics, current cigarette smoking, current ENDS use, and past-year cigarette smoking cessation attempts. We estimated the prevalence of current cigarette smoking in the full sample by socio-demographics. We also estimated the prevalence of daily ENDS use among current smokers (n = 23,232) and those who attempted to quit smoking in the past year (n = 9,341) by socio-demographics. Multivariable logistic regression models were used to assess associations between daily ENDS use and socio-demographics. Prevalence of daily ENDS use was low: 1-6% among current smokers and 2-9% among those who made a past-year quit attempt, across socio-demographics. Hispanic (Adjusted odds ratio [AOR] = 0.45, 95% confidence interval [CI] = 0.29-0.69) and non-Hispanic black smokers (AOR = 0.38, 95% CI = 0.23-0.61) were less likely than non-Hispanic white smokers to use ENDS daily. Similar associations were observed among current smokers who made a past-year quit attempt (p < 0.05). Low prevalence of daily ENDS use suggests that ENDS may only promote smoking cessation in a small fraction of smokers. Lower prevalence of daily ENDS use among non-Hispanic black smokers may worsen race-related cigarette smoking disparities.
Project description:INTRODUCTION:Evidence indicates e-cigarettes can help people quit smoking; however, more confirmatory trials are needed. To date, no trials have evaluated the effectiveness and safety of combining nicotine patches with e-cigarettes (with and without nicotine) for smoking cessation. METHODS AND ANALYSIS:This study is a pragmatic, three-arm, community-based, single-blind, randomised trial undertaken in New Zealand. Eligible participants are daily/non-daily smokers, aged ≥18 years, naive e-cigarette users and motivated to quit smoking in the next 2 weeks. Participants (n=1809), recruited using multi-media advertising, are randomised to 14 weeks of (1) 21 mg nicotine patches (n=201); (2) 21 mg nicotine patches+18 mg/mL nicotine e-cigarette (n=804); or (3) 21 mg nicotine patches+nicotine free e-cigarette (n=804). Participants receive weekly withdrawal-oriented behavioural support calls for 6 weeks post-randomisation. The primary outcome is self-reported biochemically verified continuous abstinence (CA) at 6 months post quit-date. The primary comparison is nicotine patch + nicotine e-cigarette versus nicotine patch + nicotine free e-cigarette, and the secondary comparison is nicotine patch versus nicotine patch +nicotine e-cigarette (90% power, p=0.05, to detect an absolute difference in 6 month CA rates of 8% and 15% respectively). Secondary outcomes, collected by phone interview at quit date, then 1, 3, 6 and 12 months post-quit date, include self-reported CA, 7 day point prevalence abstinence, cigarettes per day (if smoking, or when smoking for non-daily smokers), time to relapse (if returned to smoking), belief in ability to quit, use of other cessation support, side effects/serious adverse events, treatment compliance, seeking additional support around e-cigarette use, daily use of both e-cigarettes and cigarettes, use of treatment past 14 weeks, views on treatment and recommendation to others, weight and cost-per-quitter. ETHICS AND DISSEMINATION:The Northern A Health and Disability Ethics Committee approved the trial. Findings will be disseminated through publication, conference/meeting presentations, and media. TRIAL REGISTRATION NUMBER:NCT02521662; Pre-results.
Project description:Background:Smoking cessation improves morbidity and mortality among smokers who achieve long-term abstinence. Many smokers are using electronic cigarettes (e-cigarettes) to attempt to quit, despite a lack of data concerning their efficacy and safety for smoking cessation. Methods:The Evaluating the Efficacy of E-Cigarette use for Smoking Cessation (E3) trial is a multicentre randomized controlled trial (NCT02417467) with a treatment period of 12 weeks and follow-up of 52 weeks. A total of 376 participants motivated to quit smoking were enrolled at 17 Canadian centres (November 2016 to September 2019). Participants were randomized (1:1:1) to 1 of 3 treatment arms: nicotine e-cigarettes, non-nicotine e-cigarettes, or no e-cigarettes. All groups received individual counselling. Treatment allocation was double-blind for the e-cigarette groups. The trial includes follow-ups by telephone at weeks 1, 2, 8, and 18, and clinic visits at weeks 4, 12, 24, and 52. The primary endpoint is to compare nicotine e-cigarettes to counselling alone in terms of biochemically validated point-prevalence smoking abstinence at 12 weeks; the primary endpoint was changed from 52 weeks after early termination (77% of targeted enrollment) due to a prolonged delay in e-cigarette manufacturing. The secondary objectives are to examine the efficacy of nicotine and non-nicotine e-cigarettes in terms of point-prevalence and continuous smoking abstinence, and reduction in daily cigarette consumption at all follow-ups through week 52, and to describe the occurrence of adverse events. Conclusion:The E3 trial will provide regulators, health care professionals, and smokers with important information about the efficacy and safety of e-cigarettes for smoking cessation.
Project description:BACKGROUND:Electronic cigarettes (EC) may aid some smokers in reducing combustible tobacco use. Smokers with psychiatric co-morbidities tend to have higher nicotine dependence and worse outcomes, so may particularly benefit from alternative cessation aids. EC characteristics, like nicotine level and flavor, may influence EC's appeal to smokers. Nicotine level may impact EC's efficacy in reducing combustible cigarette use. METHODS:Non-treatment-seeking cigarette smokers with medical/psychiatric co-morbidities rated 'liking' of ECs varying in nicotine level (12?mg, 24?mg) and flavor (menthol, 'slim'-tobacco, 'burley'-tobacco), during an open-label Choice Procedure. Smokers (N?=?43) chose ECs for a 4-week take-home-trial, and used EC and/or combustible cigarettes as they wished. Analyses examined ratings and choice by nicotine level and flavor, and the relationship between consistent take-home choice of 12?mg versus 24?mg baseline demographic/smoking characteristics, and outcomes (cigarettes/day, nicotine intake, motivation to quit smoking) during take-home-trial and one-month follow-up. RESULTS:Smokers who chose menthol-flavor, tobacco-flavor and/or 24?mg nicotine e-liquids for the first take-home week rated these conditions as more 'liked' than alternative options, at baseline. Groups who chose 12?mg versus 24?mg throughout the take-home trial did not significantly differ on baseline characteristics, or smoking-related outcomes within the take-home trial, however, motivation to quit smoking increased more from baseline to one-month follow-up in choosers of higher nicotine (24?mg) ECs. CONCLUSIONS:Associations between subjective ratings and subsequent choice support feasibility of open-label choice-procedures in EC trials. Access to 12?mg or 24?mg nicotine ECs was associated with reduced smoking, and 24?mg ECs with increased motivation to quit smoking in smokers with medical/psychiatric co-morbidities.
Project description:BACKGROUND:Cigarette smoking is much more prevalent among young people experiencing homelessness than in the general population of adolescents and young adults. Although many young homeless smokers are motivated to quit, there are no empirically-evaluated smoking cessation programs for this population. It is important that any such program address the factors known to be associated with quitting-related outcomes among homeless young people, to provide ongoing support in a way that accommodates the mobility of this population, and does not rely on scarce service provider resources for its delivery. The objective of this project is to develop and pilot test a text messaging-based intervention (TMI), as an adjunct to brief cessation counseling and provision of nicotine patches, to help homeless young people who want to quit smoking. METHODS/DESIGN:This pilot study will utilize a cluster cross-over randomized controlled design with up to 80 current smokers who desire to quit and are recruited from three drop-in centers serving young people experiencing homelessness in the Los Angeles area. All participants will be provided with a minimum standard of care: a 30-min group-based smoking cessation counseling session and free nicotine replacement. Half of these smokers will then also receive the TMI, as an adjunct to this standard care, which will provide 6 weeks of ongoing support for quitting. This support includes continued and more intensive education regarding nicotine dependence, quitting smoking, and relapse; does not require additional agency resources; can be available "on demand" to users; and includes features to personalize the quitting experience. This study will investigate whether receiving the TMI adjunct to standard smoking cessation care results in greater reductions in cigarette smoking compared to standard care alone over a 3-month period. DISCUSSION:This study has the potential to address an important gap in the clinical research literature on cigarette smoking cessation and provide empirical support for using a TMI to provide ongoing assistance and support for quitting among young smokers experiencing homelessness. Trial registration ClinicalTrials.gov Identifier NCT03874585. Registered March 14, 2019, https://clinicaltrials.gov/ct2/show/record/NCT03874585.