The effects of varenicline on stress-induced and cue-induced craving for cigarettes

Varenicline and Nicotine Replacement Therapy for Smokers Admitted to Hospitals: A Randomized Clinical Trial

Importance

Varenicline is the most effective sole pharmacotherapy for smoking cessation. If used in combination with nicotine replacement therapy (NRT), cessation rates may be further improved, but the efficacy and safety of the combination need to be evaluated.

Objective

To examine whether hospitalized smokers treated with varenicline and NRT lozenges achieve higher prolonged smoking abstinence rates compared with those treated with varenicline alone.

Design, Setting, and Participants

A double-blind, placebo-controlled randomized clinical trial was conducted in adult medical or surgical inpatients of 5 Australian public hospitals with a history of smoking 10 cigarettes or more per day, interested in quitting, and available for 12-month follow-up between May 1, 2019, and May 1, 2021 (final 12-month data collection in May 2022). Data analysis was performed from June 1 to August 30, 2023.

Interventions

A 12-week varenicline regimen was initiated during hospitalization at standard doses in all participants. Participants were randomized to additionally use NRT (2 mg) or placebo lozenges if there was an urge to smoke. Behavioral support (Quitline) was offered to all participants.

Main Outcomes and Measures

The primary outcome was biochemically verified sustained abstinence at 6 months. Secondary outcomes included self-reported prolonged abstinence, 7-day point prevalence abstinence (3, 6, and 12 months), and medicine-related adverse events.

Results

A total of 320 participants (mean [SD] age, 52.5 [12.1] years; 183 [57.2%] male) were randomized. The conduct of biochemical verification was affected by COVID-19 restrictions; consequently, the biochemically verified abstinence in the intervention vs control arms (18 [11.4%] vs 16 [10.1%]; odds ratio [OR], 1.14; 95% CI, 0.56-2.33) did not support the combination therapy. The secondary outcomes in the intervention vs control arms of 7-day point prevalence abstinence at 6 months (54 [34.2%] vs 37 [23.4%]; OR, 1.71; 95% CI, 1.04-2.80), prolonged abstinence at 12 months (47 [29.9%] vs 30 [19.1%]; OR, 1.77; 95% CI, 1.05-3.00), and 7-day point prevalence abstinence at 12-months (48 [30.6%] vs 31 [19.7%]; OR, 1.79; 95% CI, 1.07-2.99) significantly improved with the combination therapy. The self-reported 6-month prolonged abstinence (61 [38.6%] vs 47 [29.7%]; OR, 1.49; 95% CI, 0.93-2.39) favored the combination therapy but was not statistically significant. Medicine-related adverse events were similar in the 2 groups (102 [74.5%] in the intervention group vs 86 [68.3%] in the control group).

Conclusions and Relevance

In this randomized clinical trial of the combination of varenicline and NRT lozenges in hospitalized adult daily smokers, the combination treatment improved self-reported abstinence compared with varenicline alone, without compromising safety, but it did not improve biochemically validated abstinence.

Trial Registration

anzctr.org.au Identifier: ACTRN12618001792213.

Effects of neuromodulation on cognitive and emotional responses to psychosocial stressors in healthy humans

Physiological and psychological stressors can exert wide-ranging effects on the human brain and behavior. Research has improved understanding of how the sympatho-adreno-medullary (SAM) and hypothalamic-pituitary-adrenocortical (HPA) axes respond to stressors and the differential responses that occur depending on stressor type. Although the physiological function of SAM and HPA responses is to promote survival and safety, exaggerated psychobiological reactivity can occur in psychiatric disorders. Exaggerated reactivity may occur more for certain types of stressors, specifically, psychosocial stressors. Understanding stressor effects and how the body regulates these responses can provide insight into ways that psychobiological reactivity can be modulated. Non-invasive neuromodulation is one way that responding to stressors may be altered; research into these interventions may provide further insights into the brain circuits that modulate stress reactivity. This review focuses on the effects of acute psychosocial stressors and how neuromodulation might be effective in altering stress reactivity. Although considerable research into stress interventions focuses on treating pathology, it is imperative to first understand these mechanisms in non-clinical populations; therefore, this review will emphasize populations with no known pathology and consider how these results may translate to those with psychiatric pathologies.

Comparative effects of varenicline or combination nicotine replacement therapy versus patch monotherapy on candidate mediators of early abstinence in a smoking cessation attempt

BACKGROUND AND AIMS

The phase-based model of smoking cessation treatment suggests that treatment needs may vary across phases (e.g. pre-cessation, cessation). This study tested the comparative effects of varenicline and combination nicotine replacement therapy (C-NRT) relative to nicotine patch monotherapy on pre-cessation and cessation phase candidate withdrawal, expectancy and motivation mediators; relations between mediators and abstinence; and indirect effects of enhanced treatments on abstinence via candidate mediators.

DESIGN

Secondary mediation analysis of data from the open-label, randomized Wisconsin Smokers' Health Study 2, a comparative effectiveness trial of varenicline or C-NRT, versus patch monotherapy, in adults who smoked, recruited via media and community outreach.

SETTING

Research clinics in Madison and Milwaukee, Wisconsin, USA.

PARTICIPANTS

A total of 1051 daily smokers motivated to quit smoking (52.5% female; mean age = 48.1, standard deviation = 11.6).

INTERVENTIONS

Twelve weeks of varenicline (n = 407) or 12 weeks of combination nicotine patch and nicotine lozenge therapy (n = 421), both compared with 12 weeks of patch control condition (n = 230), with individual smoking cessation counseling.

MEASUREMENTS

The primary abstinence outcome was biochemically verified 7-day point-prevalence abstinence 4 weeks post-target quit day (TQD). Candidate mediators (craving, positive smoking expectancies, withdrawal symptoms, and quitting motivation) were assessed via ecological momentary assessment from 1 week prior (pre-cessation phase) to 4 weeks after (cessation phase) the TQD.

FINDINGS

Pre-cessation and cessation mean levels and slopes of craving [adjusted odds ratio (aOR) = 0.34-0.79], smoking expectancies (aOR = 0.46-0.79) and quitting motivation (aOR = 1.35-7.21) significantly predicted 4-week post-TQD abstinence (P < 0.05). Significant varenicline mediation occurred via greater suppression in pre-cessation craving [mediated effect (ab) = 0.09, standard error (SE) = 0.03, 95% confidence interval (CI) = 0.04-0.14] and smoking expectancies (ab = 0.06, SE = 0.02, 95% CI = 0.02-0.12). C-NRT mediation occurred via greater reduction in pre-post-TQD changes in craving (ab = 0.04, SE = 0.02, 95% CI = 0.01-0.08) and expectancies (ab = 0.03, SE = 0.02, 95% CI = 0.001-0.07), relative to patch monotherapy.

CONCLUSION

Among adult smokers seeking to quit, varenicline seems to work through its effects on suppression of craving and smoking expectancies pre-cessation while combination nicotine replacement therapy mediation seems to work through cessation-related reduction in craving and smoking expectancies changes.

The efficacy and safety of varenicline alone versus in combination with nicotine lozenges for smoking cessation among hospitalised smokers (VANISH): study protocol for a randomised, placebo-controlled trial

INTRODUCTION

Smoking is a leading cause of premature deaths globally. The health benefits of smoking cessation are many. However, majority of quit attempts are unsuccessful. One way to potentially improve success rates is to evaluate new combinations of existing smoking cessation therapies that may work synergistically to decrease the intensity of withdrawal symptoms and cravings.

AIMS

To evaluate the feasibility, efficacy and safety of the combination of varenicline and nicotine replacement therapy (NRT) lozenges versus varenicline alone in assisting hospitalised smokers to quit.

METHODS AND ANALYSIS

This is a multicentre, randomised, placebo-controlled trial. Adults with a history of smoking ≥10 cigarettes per day on average in the 4 weeks prior to their hospitalisation will be recruited. Participants will be randomly assigned to either the intervention group and will receive varenicline and NRT lozenges, or the control group and will receive varenicline and placebo lozenges. All participants will be actively referred to behavioural support from telephone Quitline. Participants are followed up at 1 and 3 weeks and 3, 6 and 12 months from the start of treatment. The primary outcome is carbon monoxide validated prolonged abstinence from 2 weeks to 6 months after treatment initiation. Secondary outcomes include self-reported and biochemically validated prolonged and point prevalence abstinence at 3, 6 and 12 months, self-reported adverse events, withdrawal symptoms and cravings, adherence to treatment, Quitline sessions attended and others. According to the Russell Standard, all randomised participants will be accounted for in the primary intention-to-treat analysis.

ETHICS AND DISSEMINATION

The trial will be conducted in compliance with the protocol, the principles of Good Clinical Practice, the National Health and Medical Research Council National Statement on Ethical Conduct in Human Research (updated 2015) and the Australian Code for the Responsible Conduct of Research (2018). Approval will be sought from the Human Ethics Committees of all the participating hospitals and the university. Written informed consent will be obtained from each participant at the time of recruitment.

TRIAL REGISTRATION NUMBER

Australia New Zealand Clinical Trials Registry (ACTRN12618001792213).

Baclofen-induced Changes in the Resting Brain Modulate Smoking Cue Reactivity: A Double-blind Placebo-controlled Functional Magnetic Resonance Imaging Study in Cigarette Smokers

Objective

Smoking cue-(SC) elicited craving can lead to relapse in SC-vulnerable individuals. Thus, identifying treatments that target SC-elicited craving is a top research priority. Reduced drug cue neural activity is associated with recovery and is marked by a profile of greater tonic (resting) activation in executive control regions, and increased connectivity between executive and salience regions. Evidence suggests the GABA-B agonist baclofen can reduce drug cue-elicited neural activity, potentially through its actions on the resting brain. Based on the literature, we hypothesize that baclofen’s effects in the resting brain can predict its effects during SC exposure.

Methods

In this longitudinal, double blind, placebo-controlled neuropharmacological study 43 non-abstinent, sated treatment-seeking cigarette smokers (63% male) participated in an fMRI resting-state scan and a SC-reactivity task prior to (T1) and 3 weeks following randomization (T2; baclofen: 80 mg/day; n = 21). Subjective craving reports were acquired before and after SC exposure to explicitly examine SC-induced craving.

Results

Whole-brain full-factorial analysis revealed a group-by-time interaction with greater resting brain activation of the right dorsolateral prefrontal cortex (dlPFC) at T2 in the baclofen group (BAC) (p_FWEcorr = 0.02), which was associated with reduced neural responses to SCs in key cue-reactive brain regions; the anterior ventral insula and ventromedial prefrontal cortex (p_FWEcorr < 0.01). BAC, but not the placebo group reported decreased SC-elicited craving (p = 0.02).

Conclusion

Results suggest that baclofen mitigates the reward response to SCs through an increase in tonic activation of the dlPFC, an executive control region. Through these mechanisms, baclofen may offer SC-vulnerable smokers protection from SC-induced relapse.

Effect of nicotine lozenge use prior to smoking cue presentation on craving and withdrawal symptom severity

BACKGROUND

Smokers are often advised to use nicotine lozenge after cravings or withdrawal symptoms are present, which may be too late to prevent lapses. This study assesses if lozenge use prior to smoking cue exposure attenuates cue-induced increases in symptom severity.

METHODS

In this randomized, cross-over study, participants completed three laboratory sessions at which they proceeded through 4 "rooms" in a virtual reality environment. The first and last "rooms" contained neutral cues and the others contained smoking cues. At one session, a 4 mg nicotine lozenge was not given until after cue exposure (to approximate current use: i.e., after craving and withdrawal symptoms occur). At the other two sessions either a nicotine or placebo lozenge was used 15 min before cue exposure procedures. Craving and withdrawal symptoms were measured throughout each laboratory session.

RESULTS

Of 58 participants randomized; 40 completed all 3 labs. Absolute levels of craving and withdrawal symptom severity during cue exposure were lower when placebo or active lozenge was used prior to cue presentation procedures vs. no treatment until after cue presentation procedures (all p-values <0.05). There were no differences among conditions in the magnitude of symptom severity increase occurring between the first neutral room and the cue rooms.

CONCLUSIONS

Lozenge use prior to cue exposure may minimize cue induced symptom severity but when taken 15 min prior to cues the decrease is not different than placebo. Research is needed to determine if another time-frame relative to cue exposure would be more effective.

Facilitated Extinction Training to Improve Pharmacotherapy for Smoking Cessation: A Pilot Feasibility Trial

Introduction

Varenicline reduces smoking satisfaction during the pre-cessation run-in period, which may contribute to extinction of cravings and smoking behavior. Research indicates that efficacy is enhanced when the run-in period is increased from 1 to 4 weeks, providing a longer extinction opportunity. We hypothesized that efficacy could be further enhanced by harnessing basic and applied research on extinction. We developed a pre-cessation extinction-facilitating intervention and tested its feasibility in a pilot trial.

Methods

The facilitated extinction (FE) intervention comprised brief counseling and workbook-recommending strategies to maximize extinction processes during the run-in, including instructions to smoke at a normal rate across contexts and cues, and use of an extinction cue to enhance generalization. Participants were randomly assigned to one of three varenicline interventions: standard (1-week run-in), extended (4-week run-in), and extended + FE. Interventions were delivered prior to the target quit date (TQD). Assessments were conducted in weeks 1 and 4 pre-TQD and 1 and 3 months post-TQD, with focus on feasibility indices.

Results

Recruitment and retention goals were met (N = 58). Treatment satisfaction was high across groups. The majority of FE participants adhered to instructions and maintained their usual smoking rate during the run-in period. Greater decreases in craving and smoking satisfaction were observed among participants in both extended groups versus the standard group (p < .005).

Conclusions

Feasibility was demonstrated. Participants adhered to the FE intervention, thereby optimizing the number and variety of extinction trials. Findings support testing the novel FE smoking cessation intervention in a fully powered trial.

Implications

This study expands the research on the clinical benefits of extending the pre-cessation run-in period of varenicline. It introduces the hypothesis that further benefit might be achieved by translating basic behavioral research, as well as cue-exposure research and therapy for other disorders, to improve the extinction and generalization processes thought to underlie much of varenicline's effect. A FE intervention was developed and found acceptable to smokers and feasible to implement in a research setting. The study sets the stage for a subsequent randomized controlled trial.

A Preliminary Examination of Nicotine-Free Electronic Cigarette Use During Cessation From Combustible Cigarettes

Despite the availability of smoking cessation strategies, smoking cue-induced craving remains a relatively untreated relapse risk factor. Utilizing nicotine-free electronic cigarettes (e-cigarettes) to extinguish the motivational influence of smoking cues may be a viable approach to address cue reactivity. In this pilot study, 26 daily tobacco smokers used nicotine-free e-cigarettes while being maintained on daily transdermal sustained-release nicotine replacement therapy (NRT) to mitigate pharmacological withdrawal. Sensitivity to cue-induced craving, measured by the rise in craving after a visual cue exposure task, was assessed at a baseline visit after smoking as usual and again after 2 weeks of nicotine-free e-cigarette and NRT use. Participants' pattern and amount of tobacco cigarette smoking were evaluated on both visits and 1 month posttreatment. Cue-induced craving significantly decreased after the 2-week intervention, yet withdrawal scores increased during this time. One month after study completion, participants continued to report significantly lower overall cigarette craving and conventional tobacco cigarette use. Including the 34.8% that were totally abstinent, 65.2% reported smoking fewer than 10 cigarettes per week (compared to 87.2 per week at baseline for the entire group). A linear regression revealed that greater baseline cue-induced craving predicted better outcomes, whereas more withdrawal at the e-cigarette visit was related to more smoking at 1 month. This proof-of-concept pilot study suggests that the addition of ad libitum nicotine-free e-cigarettes to an existing strategy of transdermal NRT may attenuate cue-induced craving for tobacco smoking. A larger sample that is powered for detecting additional factors and longer-term outcomes is warranted.

Anti-stress neuropharmacological mechanisms and targets for addiction treatment: A translational framework

Stress-related substance use is a major challenge for treating substance use disorders. This selective review focuses on emerging pharmacotherapies with potential for reducing stress-potentiated seeking and consumption of nicotine, alcohol, marijuana, cocaine, and opioids (i.e., key phenotypes for the most commonly abused substances). I evaluate neuropharmacological mechanisms in experimental models of drug-maintenance and relapse, which translate more readily to individuals presenting for treatment (who have initiated and progressed). An affective/motivational systems model (three dimensions: valence, arousal, control) is mapped onto a systems biology of addiction approach for addressing this problem. Based on quality of evidence to date, promising first-tier neurochemical receptor targets include: noradrenergic (α1 and β antagonist, α2 agonist), kappa-opioid antagonist, nociceptin antagonist, orexin-1 antagonist, and endocannabinoid modulation (e.g., cannabidiol, FAAH inhibition); second-tier candidates may include corticotropin releasing factor-1 antagonists, serotonergic agents (e.g., 5-HT reuptake inhibitors, 5-HT3 antagonists), glutamatergic agents (e.g., mGluR2/3 agonist/positive allosteric modulator, mGluR5 antagonist/negative allosteric modulator), GABA-promoters (e.g., pregabalin, tiagabine), vasopressin 1b antagonist, NK-1 antagonist, and PPAR-γ agonist (e.g., pioglitazone). To address affective/motivational mechanisms of stress-related substance use, it may be advisable to combine agents with actions at complementary targets for greater efficacy but systematic studies are lacking except for interactions with the noradrenergic system. I note clinically-relevant factors that could mediate/moderate the efficacy of anti-stress therapeutics and identify research gaps that should be pursued. Finally, progress in developing anti-stress medications will depend on use of reliable CNS biomarkers to validate exposure-response relationships.

Effects of varenicline on subjective craving and relative reinforcing value of cigarettes

BACKGROUND

Varenicline is an FDA approved medication for the treatment of nicotine dependence. While the efficacy and safety of this medication have been demonstrated, success rates remain low, and efforts to understand mechanisms of efficacy are in progress. A behavioral economics framework is one unique way to examine how demand for a drug changes under different circumstances. Therefore, the current randomized placebo-controlled, cross-over study aimed to examine effects of varenicline on subjective cigarette craving and objective demand for cigarettes measured by a hypothetical behavioral economic task as well as associations between subjective craving and objective demand.

METHOD

Non-treatment seeking (n = 37) daily smokers (>10 cigarettes per day) completed a measure of subjective craving for cigarettes and the Cigarette Purchase Task following overnight nicotine abstinence. Participants completed these measures after 10 days on varenicline (1 mg twice per day) and matched placebo.

RESULTS

Analyses revealed a significant reduction in subjective craving for cigarettes while on varenicline (p = 0.01), as compared to placebo, and a sex effect such that females exhibited greater craving than males (p = 0.03). However, there were no medication × sex effects (p = 0.84). Analyses of objective demand for cigarettes found varenicline reduced maximum expenditure (Omax) (p = 0.03). Subjective craving was also associated with various indices of demand.

CONCLUSION

Results demonstrated varenicline's efficacy in attenuating subjective craving and objective demand for cigarettes and highlight the partial overlap between dimensions of acute drug motivation, namely subjective craving and behavioral economic indices of cigarette demand.

Exacerbated Craving in the Presence of Stress and Drug Cues in Drug-Dependent Patients

In addiction, risk factors for craving and use include stress and drug-related cues. Stress and cues have additive or more-than-additive effects on drug seeking in laboratory animals, but, surprisingly, seem to compete with one another (ie, exert less-than-additive effects) in human laboratory studies of craving. We sought heretofore elusive evidence that human drug users could show additive (or more-than-additive) effects of stress and cues on craving, using ecological momentary assessment (EMA). Outpatients (N=182) maintained on daily buprenorphine or methadone provided self-reports of stress, craving, mood, and behavior on electronic diaries for up to 16 weeks. In three randomly prompted entries (RPs) per day, participants reported the severity of stress and craving and whether they had seen or been offered opioids, cocaine, cannabis, methamphetamine, alcohol, or tobacco. In random-effects models controlling for between-person differences, we tested effects of momentary drug-cue exposure and stress (and their interaction) on momentary ratings of cocaine and heroin craving. For cocaine craving, the Stress × Cue interaction term had a positive mean effect across participants (M=0.019; CL95 0.001-0.036), denoting a more-than-additive effect. For heroin, the mean was not significantly greater than 0, but the confidence interval was predominantly positive (M=0.019; CL95 -0.007-0.044), suggesting at least an additive effect. Heterogeneity was substantial; qualitatively, the Stress × Cue effect appeared additive for most participants, more than additive for a sizeable minority, and competitive in very few. In the field, unlike in human laboratory studies to date, craving for cocaine and heroin is greater with the combination of drug cues and stress than with either alone. For a substantial minority of users, the combined effect may be more than additive.

Effects of smoking and paroxetine on stress-induced craving and withdrawal symptoms

Background

When smokers relapse, many cite stressful circumstances as the cause. Most smoking cessation medications do not prevent stress induced increases in craving and withdrawal symptom severity; however the effect of smoking prior to stress exposure on symptom severity is unclear.

Methods

We examined how smoking a cigarette immediately prior to a stressful task affects craving and withdrawal symptom severity by analyzing data from a double-blind, crossover study assessing paroxetine's effects on the physiological response to the combination of stress and smoking. Measures were obtained prior to and following smoking / stress exposure and following a subsequent 30 minute period at two laboratory sessions (i.e., after one month each of paroxetine and placebo).

Results

Among study completers (n=63), severity of craving decreased from the beginning of the session to immediately following the smoking / stress exposure (p<0.01) and severity of smoking urges decreased from the beginning to the end of the laboratory session (p<0.001). Withdrawal symptoms were less severe while taking paroxetine vs. placebo (p<0.05) but no treatment x time effects were observed.

Conclusions

Additional research is needed to identify interventions that could similarly decrease stress induced craving in order to determine if smoking cessation rates can be increased.

Current insights into the mechanisms and development of treatments for heavy drinking cigarette smokers

There is a strong association between cigarette smoking and alcohol use at the epidemiological, behavioral, and molecular levels, and this co-use creates substantial impediments to smoking cessation among smokers who are also heavy drinkers. Compared with individuals who only smoke, those who both drink and smoke heavily experience more severe health consequences and have greater difficulty in quitting smoking. During smoking abstinence, greater alcohol use is associated with decreased odds of smoking cessation, and smokers are substantially more likely to experience a smoking lapse during drinking episodes. As heavy drinking smokers are less responsive to the currently available pharmacological treatments, this subgroup of high-risk substance users possesses a unique clinical profile and treatment needs. Thus, treatment development for heavy drinking smokers represents a significant and understudied research area within the field of smoking cessation. This review will briefly describe findings from epidemiological, behavioral, and molecular studies illustrating alcohol and tobacco co-use and identify how the behavioral and neurobiological mechanisms underlying the interaction of alcohol and nicotine may inform the development of targeted treatments for this unique population of smokers.

Laboratory-induced stress and craving among individuals with prescription opioid dependence

BACKGROUND

Stress and conditioned drug cues have been implicated in the initiation, maintenance and relapse to substances of abuse. Although stress and drug cues are often encountered together, little research exists on whether stress potentiates the response to drug cues.

METHOD

Participants (N=75) were 39 community recruited individuals with current prescription opioid (PO) dependence and 36 healthy controls. Participants stayed overnight in the hospital for one night and then completed laboratory testing the following morning. During laboratory testing, participants were randomly assigned to a stress task (Trier Social Stress Task; TSST) or a no-stress condition. Following the stress manipulation, all participants completed a PO cue paradigm. Immediately before and after the stress and cue tasks, the following were assessed: subjective (stress, craving, anger, sadness, happiness), physiological (heart rate, blood pressure, galvanic skin response), and neuroendocrine responses (cortisol and dehydroepiandrosterone).

RESULTS

Internal validity of the stress task was demonstrated, as evidenced by significantly higher subjective stress, as well as cortisol, heart rate and blood pressure in the TSST compared to the no-stress group. Individuals with PO dependence evidenced significantly greater reactivity to the stress task than controls. Craving increased significantly in response to the drug cue task among PO participants. No stress×cue interaction was observed.

CONCLUSIONS

In this study, heightened stress reactivity was observed among individuals with PO dependence. Exposure to acute stress, however, did not potentiate craving in response to conditioned drug cues.

Emotion differentiation and intensity during acute tobacco abstinence: A comparison of heavy and light smokers

The ability to recognize and label discrete emotions, termed emotion differentiation, is particularly pertinent to overall emotion regulation abilities. Patterns of deficient emotion differentiation have been associated with mood and anxiety disorders but have yet to be examined in relation to nicotine dependence. This study employed ecological momentary assessment to examine smokers' subjective experience of discrete emotions during 24-h of forced tobacco abstinence. Thirty daily smokers rated their emotions up to 23 times over the 24-hour period, and smoking abstinence was biologically verified. From these data, we computed individual difference measures of emotion differentiation, overall emotion intensity, and emotional variability. As hypothesized, heavy smokers reported poorer negative emotion differentiation than light smokers (d=0.55), along with more intense negative emotion (d=0.97) and greater negative emotion variability (d=0.97). No differences were observed in positive emotion differentiation. Across the sample, poorer negative emotion differentiation was associated with greater endorsement of psychological motives to smoke, including negative and positive reinforcement motives, while positive emotion differentiation was not.

Modeling naturalistic craving, withdrawal, and affect during early nicotine abstinence: A pilot ecological momentary assessment study

Despite the critical role of withdrawal, craving, and positive affect (PA) and negative affect (NA) in smoking relapse, relatively little is known about the temporal and predictive relationship between these constructs within the first day of abstinence. This pilot study aims to characterize dynamic changes in withdrawal, craving, and affect over the course of early abstinence using ecological momentary assessment. Beginning immediately after smoking, moderate and heavy smoking participants (n = 15 per group) responded to hourly surveys assessing craving, withdrawal, NA, and PA. Univariate and multivariate multilevel random coefficient modeling was used to describe the progression of craving, withdrawal/NA, and PA and to test correlations between these constructs at the subject level over the course of early abstinence. Heavy smokers reported greater craving from 1-4 hr of abstinence and greater withdrawal/NA after 3 or more hours as compared with moderate smokers. Level of withdrawal/NA was strongly positively associated with craving, and PA was negatively correlated with craving; however, the temporal dynamics of these correlations differed substantially. The association between withdrawal/NA and craving decreased over early abstinence, whereas the reverse was observed for PA. These findings can inform experimental studies of nicotine abstinence as well as their clinical applications to smoking cessation efforts. In particular, these results help to elucidate the role of PA in nicotine abstinence by demonstrating its independent association with nicotine craving over and above withdrawal/NA. If supported by future studies, these findings can refine experimental methods and clinical approaches for smoking cessation.

Effects of varenicline and cognitive bias modification on neural response to smoking-related cues: study protocol for a randomized controlled study

Background

Smoking-related cues can trigger drug-seeking behaviors, and computer-based interventions that reduce cognitive biases towards such cues may be efficacious and cost-effective cessation aids. In order to optimize such interventions, there needs to be better understanding of the mechanisms underlying the effects of cognitive bias modification (CBM). Here we present a protocol for an investigation of the neural effects of CBM and varenicline in non-quitting daily smokers.

Methods/Design

We will recruit 72 daily smokers who report smoking at least 10 manufactured cigarettes or 15 roll-ups per day and who smoke within one hour of waking. Participants will attend two sessions approximately one week apart. At the first session participants will be screened for eligibility and randomized to receive either varenicline or a placebo over a seven-day period. On the final drug-taking day (day seven) participants will attend a second session and be further randomized to one of three CBM conditions (training towards smoking cues, training away from smoking cues, or control training). Participants will then undergo a functional magnetic resonance imaging scan during which they will view smoking-related pictorial cues. Primary outcome measures are changes in cognitive bias as measured by the visual dot-probe task, and neural responses to smoking-related cues. Secondary outcome measures will be cognitive bias as measured by a transfer task (modified Stroop test of smoking-related cognitive bias) and subjective mood and cigarette craving.

Discussion

This study will add to the relatively small literature examining the effects of CBM in addictions. It will address novel questions regarding the neural effects of CBM. It will also investigate whether varenicline treatment alters neural response to smoking-related cues. These findings will inform future research that can develop behavioral treatments that target relapse prevention.

Trial registration

Registered with Current Controlled Trials: ISRCTN65690030. Registered on 30 January 2014.

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.

Varenicline effects on drinking, craving and neural reward processing among non-treatment-seeking alcohol-dependent individuals

RATIONALE

The α4β2 nicotinic acetylcholine receptor partial agonist varenicline has been reported to reduce drinking among both heavy-drinking smokers and primary alcoholics, and this effect may be related to varenicline-mediated reduction of alcohol craving. Among smokers, varenicline has been reported to modulate cigarette cue-elicited brain activation in several reward-related areas.

OBJECTIVES

This pilot study tested varenicline's effects on drinking, alcohol craving, and alcohol cue-elicited activation of reward-related brain areas among non-treatment-seeking alcohol-dependent individuals.

METHODS

Thirty-five such individuals (mean age = 30, 57 % male, 76 % heavy drinking days in the past month, 15 smokers) were randomized to either varenicline (titrated to 2 mg) or placebo for 14 days, and were administered an alcohol cue reactivity fMRI task on day 14. A priori regions of interest (ROIs) were bilateral and medial orbitofrontal cortex (OFC), right ventral striatum (VS), and medial prefrontal cortex (mPFC).

RESULTS

Despite good medication adherence, varenicline did not reduce heavy drinking days or other drinking parameters. It did, however, increase self-reported control over alcohol-related thoughts and reduced cue-elicited activation bilaterally in the OFC, but not in other brain areas.

CONCLUSIONS

These data indicate that varenicline reduces alcohol craving and some of the neural substrates of alcohol cue reactivity. However, varenicline effects on drinking mediated by cue-elicited brain activation and craving might be best observed among treatment-seekers motivated to reduce their alcohol consumption.

Scientific overview: 2013 BBC plenary symposium on tobacco addiction

Nicotine dependence plays a critical role in addiction to tobacco products, and thus contributes to a variety of devastating tobacco-related diseases (SGR 2014). Annual costs associated with smoking in the US are estimated to be between $289 and $333 billion. Effective interventions for nicotine dependence, especially in smokers, are a critical barrier to the eradication of tobacco-related diseases. This overview highlights research presented at the Plenary Symposium of Behavior, Biology and Chemistry: Translational Research in Addiction Conference (BBC), hosted by the UT Health Science Center San Antonio, on March 9-10, 2013. The Plenary Symposium focused on tobacco addiction, and covered topics ranging from basic science to national policy. As in previous years, the meeting brought together globally-renowned scientists, graduate student recruits, and young scientists from underrepresented populations in Texas and other states with the goal of fostering interest in drug addiction research in young generations.

Opportunities for the development of neuroimmune therapies in addiction

Studies have implicated neuroinflammatory processes in the pathophysiology of various psychiatric conditions, including addictive disorders. Neuroimmune signaling represents an important and relatively poorly understood biological process in drug addiction. The objective of this review is to update the field on recent developments in neuroimmune therapies for addiction. First, we review studies of neuroinflammation in relation to alcohol and methamphetamine dependence followed by a section on neuroinflammation and accompanying neurocognitive dysfunction in HIV infection and concomitant substance abuse. Second, we provide a review of pharmacotherapies with neuroimmune properties and their potential development for the treatment of addictions. Pharmacotherapies covered in this review include ibudilast, minocycline, doxycycline, topiramate, indomethacin, rolipram, anakinra (IL-1Ra), peroxisome proliferator-activated receptor agonists, naltrexone, and naloxone. Lastly, summary and future directions are provided with recommendations for how to efficiently translate preclinical findings into clinical studies that can ultimately lead to novel and more effective pharmacotherapies for addiction.