Effect of impulsivity on craving and behavioral reactivity to smoking cues

Introduction Nearly 25% of American adults remain regular smokers. Current smokers may be especially likely to possess characteristics that impair their ability to quit, such as impulsivity. Impulsive individuals may be overly prone to smoke because they are particularly drawn to rewarding stimuli and related cues. The aim of this study was to test the hypothesis that more impulsive smokers are more responsive to cigarette cues than other smokers. Materials and methods In a repeated measures design, 60 euthymic, adult smokers (50% female) were exposed to a smoking cue and a neutral cue in two experimental sessions. Cue reactivity was operationalized as changes in cigarette craving and preference for immediate vs delayed smoking after cue exposure. Results Impulsivity predicted a heightened craving response to both cues but particularly the smoking cue (t [161] = 3.21, p = 0.002). Smokers with high levels of impulsivity exhibited a greater preference for immediate rewards over larger, delayed rewards in terms of both hypothetical (t [58] = 5.99, p = 0.001) and actual (z = 3.02, p = 0.003) rewards. Conclusion These data suggest that increased reactivity to environmental smoking cues contributes to the link between impulsivity and smoking.     

Reactivity to nicotine cues over repeated cue reactivity sessions

The present study investigated whether reactivity to nicotine-related cues would attenuate across four experimental sessions held 1 week apart. Participants were nineteen non-treatment seeking, nicotine-dependent males. Cue reactivity sessions were performed in an outpatient research center using in vivo cues consisting of standardized smoking-related paraphernalia (e.g., cigarettes) and neutral comparison paraphernalia (e.g., pencils). Craving ratings were collected before and after both cue presentations while physiological measures (heart rate, skin conductance) were collected before and during the cue presentations. Although craving levels decreased across sessions, smoking-related cues consistently evoked significantly greater increases in craving relative to neutral cues over all four experimental sessions. Skin conductance was higher in response to smoking cues, though this effect was not as robust as that observed for craving. Results suggest that, under the described experimental parameters, craving can be reliably elicited over repeated cue reactivity sessions.     

Assessing reactivity to virtual reality alcohol based cues

The use of virtual reality (VR) programs in behavioral science research has been gaining prominence over the past several years. In the field of substance abuse, VR cue reactivity programs have been successfully tested for feasibility in nicotine and cocaine dependent samples. Seeking to expand VR applications in alcohol cue research, a novel VR alcohol cue reactivity assessment system incorporating visual, auditory, and olfactory stimuli was developed and tested. In a controlled trial, 40 non-treatment-seeking drinkers with alcohol use disorders were exposed to VR alcohol cue environments. Subjective craving, attention to alcohol cues, and level of presence (realism of experience) in VR were assessed across the environments. Overall, subjective craving for alcohol increased across the VR alcohol-related cue environments versus VR neutral cue environments. Participants reported high levels of presence in VR, indicating that the environments were perceived as realistic and compelling. These initial findings support the use of VR based cue reactivity environments for use in alcohol cue-based treatment and research.     

Pretreatment cue reactivity predicts end-of-treatment smoking

Although a substantial body of literature has established a relationship between cue reactivity and theoretically relevant addiction variables, the association with treatment process variables remains largely unexplored. In the current investigation, 62 smokers participated in a smoking cue reactivity study, and subsequently enrolled in a smoking cessation program. Hierarchical regressions revealed mean heart rate during the cue presentation phase of the laboratory-based assessment predicted final session smoking rate and expired CO level. Fagerström Tolerance Questionnaire score also predicted final session smoking rate. To the extent that rate reduction serves as an index of treatment progress, it may be of value in future cue reactivity research.     

Exposure to smoking cues: cardiovascular and autonomic effects

Laboratory exposures to smoking cues have been shown to reliably induce self-reported cigarette cravings among smokers, a model of environmentally triggered urges to smoke that can contribute to poorer cessation success. Several studies have also demonstrated that cue exposures give rise to changes in heart rate and blood pressure. Few studies, however, have investigated possible cue effects on heart rate and blood pressure variability (HRV and BPV). Particularly intriguing in this regard are cardiac oscillations in the low (i.e., 0.04-0.15 Hz), and high (i.e., 0.15-0.50 Hz) frequency range, which are thought to reflect components of autonomic control and response to environmental challenges. A closer examination of cardiovascular reactivity may thus help characterize the autonomic response to smoking cue exposure. To that end, an experimental study was conducted in which nicotine dependent daily smokers (n=98) were exposed to guided imagery of neutral and smoking situations, while continuous, noninvasive, beat-to-beat cardiovascular data were collected. Consistent with previous research, the findings revealed significant increases in both systolic and diastolic blood pressure during smoking imagery, relative to neutral imagery. In addition, power spectral density analyses of heart rate and blood pressure variability revealed elevated HRV and BPV in both the low- and high-frequency ranges during the smoking imagery. The results suggest the presence of an autonomic component to smoking cue reactivity, and also raise the possibility of long-term negative cardiac consequences for smokers who ubiquitously encounter cues in their daily environments.     

Selective attention to smoking cues in former smokers

Repeated drug use modifies the emotional and cognitive processing of drug-associated cues. These changes are supposed to persist even after prolonged abstinence. Several studies demonstrated that smoking cues selectively attract the attention of smokers, but empirical evidence for such an attentional bias among successful quitters is inconclusive. Here, we investigated whether attentional biases persist after smoking cessation. Thirty-eight former smokers, 34 current smokers, and 29 non-smokers participated in a single experimental session. We used three measures of attentional bias for smoking stimuli: A visual probe task with short (500 ms) and long (2000 ms) picture stimulus durations, and a modified Stroop task with smoking-related and neutral words. Former smokers and current smokers, as compared to non-smokers, showed an attentional bias in visual orienting to smoking pictures in the 500 ms condition of the visual probe task. The Stroop interference index of smoking words was negatively related to nicotine dependence in current smokers. Former smokers and mildly dependent smokers, as compared to non-smokers, showed increased interference by smoking words in the Stroop task. Neither current nor former smokers showed an attentional bias in maintained attention (2000 ms visual probe task). In conclusion, even after prolonged abstinence smoking cues retain incentive salience in former smokers, who differed from non-smokers on two attentional bias indices. Attentional biases in former smokers operate mainly in early involuntary rather than in controlled processing, and may represent a vulnerability factor for relapse. Therefore, smoking cessation programs should strengthen self-control abilities to prevent relapses.     

Effects of mecamylamine on human cigarette smoking and subjective ratings

Multiple measures of cigarette smoking, subjective effect and physiological effect were collected during 90-min test sessions in normal volunteers. Before sessions subjects received oral doses of mecamylamine (2.5, 5.0, 10, 20 mg) or placebo. Each dose and placebo was given three times in a randomized block sequence. Mecamylamine increased several measures of cigarette smoking, including number of cigarettes, number of puffs per cigarette, and expired air carbon monoxide level. Mecamylamine also produced modest, dose-related decreases in standing blood pressure and increases in standing heart rate. The subjective effects produced by mecamylamine were not characteristic of those of psychoactive drugs. Mecamylamine appears to have increased cigarette smoking by decreasing the effective dose level of nicotine available from cigarette smoking.     

Cue reactivity during treatment,and not impulsivity,predicts an initial lapse after treatment in alcohol use disorders

Both cue-elicited craving and impulsivity have been involved in alcohol misuse. However, their role in relapse has not been very clear. In the present study, we ask whether cue-elicited craving, impulsivity, and their interaction term predict a lapse in problem drinkers. Participants (n = 20) were former patients of the clinic, U-Center, in the Netherlands, who had completed a six-week alcohol treatment program and had an abstinence goal. While in treatment, they underwent a cue exposure paradigm in a real alcohol-related setting and their trait impulsivity was measured with the Barratt Impulsiveness Scale version 11 (BIS-11). During the follow-up assessment, patients were contacted again and asked about their alcohol drinking behavior during the first three months after the end of the treatment program. It was found that higher craving and lower trait impulsivity levels are associated with a higher probability of a lapse.     

Effect of smoking cessation and relapse on cardiovascular levels and reactivity

This study was designed to investigate the effect of smoking cessation on heart rate, blood pressure, and finger temperature absolute levels and reactivity to a range of laboratory challenges. The 148 quitters (mean age=43.3 years, mean amount smoked=24.9 cigarettes per day, mean years smoked=25.2) completed three assessments: an average of 4±2.8 days before cessation (Exam 1), an average of 2±1.0 days after cessation (Exam 2), and an average of 20±5.5 days after cessation (Exam 3). A nonsmoking group (n=39) was similarly assessed three times to control for effects related to repeated testing. Comparison of group changes from Exam 1 to Exam 2 indicated that smoking cessation produced a significant decrease in heart rate during rest and during all stressors (mean=–8.9 bpm). Those quitters who remained abstinent or smoked occasionally showed minimal changes in heart rate from Exam 2 to Exam 3, but those quitters who returned to their previous smoking level showed a significant increase in heart rate from Exam 2 to Exam 3. None of the indices of cardiovascular reactivity changed across exams, and neither did absolute levels of blood pressure or finger temperature at rest or during stressors. The possible mechanisms producing a selective heart rate decline after smoking cessation in the absence of pressor or vasodilation effects are discussed.     

Effect of tryptophan depletion on the attentional salience of smoking cues

Rationale There is increasing evidence linking cigarette craving and smoking behavior to serotonergic neurotransmission. Objectives The purpose of the current study was to examine the effects of a serotonergic challenge on the attentional salience of various cues associated with cigarettes. We hypothesized that cigarette-related word cues would be more distracting after acute tryptophan depletion than after a placebo challenge. We also hypothesized that smokers vulnerable to recurrent depression would show greater attentional bias towards these cues than smokers without a history of depression. Methods Thirty-four smokers diagnosed as having (n = 15) or lacking (n = 19) a history of DSM-IV major depressive disorder (MDD) underwent acute tryptophan depletion (ATD) and placebo challenges in double-blind and counterbalanced order 1 week apart. Five hours after consumption of each mixture, subjects completed a modified Stroop task to measure attentional bias to smoking-related, positive affect, and negative affect word cues. Stroop interference was calculated as a difference score between latencies for the motivationally salient and the neutral (furniture) word lists. Results Controlling for change in dysphoric mood from baseline to 5 h, repeated measures MANOVAs showed that ATD, as compared to placebo challenge, produced greater interference for smoking word cues [F(1,29)=4.15, p = 0.05], but not for negative [F(1,29)=2.78, p = 0.11] or positive [F(1,29)=1.60, p = 0.22] affect word cues. Conclusions Acutely compromising central serotonergic neurotransmission via ATD heightens the attentional salience of cigarette-related cues, perhaps by triggering reward and motivational deficits underlying nicotine dependence.     

d-Cycloserine attenuates reactivity to smoking cues in nicotine dependent smokers: A pilot investigation

Increasing evidence indicates that smoking cues contribute to nicotine self-administration and attenuating conditioned reactivity to smoking cues may aid abstinence of smoking and prevention of smoking relapse in individuals with nicotine dependence. Based on prior studies showing that the partial N-methyl-d-aspartate (NMDA) agonist d-cycloserine (DCS) facilitates extinction of learned fear during behavioral exposure therapy in humans and facilitates extinction of cocaine-induced conditioned place preference in animals, we evaluated whether DCS would have potential for reducing reactivity to smoking cues when combined with cue exposure treatment in humans with nicotine dependence. In this double-blind placebo-controlled pilot laboratory study, 25 smokers were recruited from the general community and randomized to DCS or placebo, plus cue exposure therapy. DCS significantly attenuated smoking cue reactivity in response to in-vivo smoking cues based on physiological reactivity and subjective urge-to-smoke ratings and led to a significantly smaller expired carbon monoxide (CO) level at the one-week follow-up compared to placebo, although exploratory analyses indicated no effect on smoking behavior overall. These findings provide promising support for DCS combined with cue exposure therapy in attenuating conditioned reactivity to smoking cues.     

抽烟对异丙酚有效靶浓度的影响

目的:观察抽烟对异丙酚有效靶浓度的影响。方法:选择择期在全麻下行上腹部手术的男患者50例,其中抽烟患者24例为A组,非抽烟患者26例为B组,在BIS监测下观察两组患者在插管前、插管后、切皮前、切皮后、术中探查、术毕时的异丙酚效应靶浓度、心率和平均动脉压。结果:两组患者的一般情况比较差异无显著性(P>0.05)。除切皮前,抽烟患者的异丙酚有效靶浓度均较非抽烟患者高(P<0.01或P<0.05),而其它各时间点的血流动力学指标无差异(P>0.05)。结论:长期抽烟使患者手术时对异丙酚的反应性降低,效应室有效靶浓度明显高于非抽烟患者,而对手术期间血流动力学无明显影响。     

Behavioral Activation System (BAS) sensitivity and reactivity to alcohol cues among hazardous drinkers

Previous research has suggested that Behavioral Activation System (BAS) sensitivity may be associated with stronger appetitive responses to alcohol cues. This study was conducted to explore whether those with higher BAS sensitivity showed greater urge and affective responses to alcohol cues and whether different types of appetitive cues moderated the magnitude of these associations. One hundred eighty-eight hazardous drinkers (90 women) were exposed to the sight and smell of their favorite alcoholic beverage during a cue exposure procedure. Participants were asked to either lean towards the beverage (Cue Only) when signaled by tones, or lift the beverage towards them (Cue+Action). BAS sensitivity was significantly associated with baseline ratings of urge and affect, and was found to be a significant predictor of urge and affect reactivity; however significant interaction effects with cue type were not observed. Results provide further evidence for the influence of individual differences in reward responsiveness on alcohol use and abuse.     

Effects of cigarette smoking status on delay discounting in schizophrenia and healthy controls

Background

Delay discounting is a measure of future-oriented decision-making and impulsivity. Cigarette smoking is associated with rapid discounting of the value of delayed outcomes. In schizophrenia, however, cigarette smoking improves certain neurocognitive impairments associated with the disorder which may explain the high smoking rates in this population. This study examined the relationship between cigarette smoking and delay discounting in schizophrenia and control participants.

Methods

A total of N = 130 participants, including those with schizophrenia (n = 68) and healthy controls (n = 62) were assessed on the Kirby Delay Discounting Task and compared across smoking status (smokers; non-smokers) and smoking history (current, former; never smokers).

Results

Smokers exhibited higher discounting rates (i.e., were more impulsive) than non-smokers of the same diagnostic group. Current and former smokers with schizophrenia exhibited similar and significantly higher discounting rates than never smokers, suggesting that in schizophrenia delay discounting is a trait-dependent phenomenon independent of current cigarette smoking. Consistent with previous studies, there was a trend for higher discounting rates in control current smokers compared to control former and never smokers.

Conclusions

Smokers with and without schizophrenia have higher rates of delay discounting than non-smokers. However, in schizophrenia, rapid delay discounting appears to be a trait associated with having ever been a smoker (i.e., current and former smoking).     

DRD4 VNTR polymorphism is associated with transient fMRI-BOLD responses to smoking cues

Rationale A dopamine receptor 4 variable number tandem repeat (DRD4 VNTR) polymorphism has been related to reactivity to smoking cues among smokers, but the effect of this genetic variation on brain responses to smoking cues has not been evaluated. Objectives The present study evaluated the relationship between carrying the DRD4 VNTR 7-repeat allele and transient functional magnetic resonance imaging (fMRI) blood-oxygen-level-dependent responses to smoking cues among adult dependent cigarette smokers. Materials and methods Smokers (n = 15) underwent fMRI scanning after 2-h abstinence. During scanning, they viewed visual smoking and control cues. A blood sample was assayed for the DRD4 VNTR polymorphism, and participants were categorized based on whether they carried one or two copies of the 7-repeat allele (DRD4 L, n = 7) or not (DRD4 S, n = 8). Results Contrasts in brain cue-reactivity (smoking minus control cues) between DRD4 groups were conducted using SPM2. Smoking cues as compared to control cues elicited transient brain responses in right superior frontal gyrus (BA 8/9/10/32), left anterior cingulate gyrus (BA 32), and right cuneus (BA 19). Exposure to smoking cues resulted in greater activation of right superior frontal gyrus (BA 10) and right insula in DRD4 L compared to DRD4 S individuals. By contrast, exposure to smoking cues among DRD4 S individuals resulted in no significant increases in activation compared to DRD4 L individuals. Conclusions These brain imaging results suggest that DRD4 VNTR polymorphism is related to transient brain responses to smoking cues in regions subserving executive and somatosensory processes.     

Effect of positive and negative affective stimuli and beverage cues on measures of craving in non treatment-seeking alcoholics

RATIONALE: Laboratory paradigms are useful for investigating mechanisms of human alcohol cue reactivity in a highly controlled environment. A number of studies have examined the effects of beverage exposure or negative affective stimuli on cue reactivity independently, but only a few have reported on interaction effects between beverage cue and affective stimuli, and none have evaluated the effects of positive stimuli on beverage cue reactivity. OBJECTIVES: To assess independent and interactive effects of both positive and negative affective stimuli and beverage cue on psychophysiological and subjective measures of reactivity in alcohol dependence. MATERIALS AND METHODS: A total of 47 non-treatment-seeking paid volunteers with current alcohol dependence participated in a within-subjects trial where each was exposed to a standardized set of pleasant, neutral, or unpleasant visual stimuli followed by alcohol or water cues. Psychophysiological cue-reactivity measures were obtained during beverage presentation, and subjective reactivity measures were taken directly following beverage presentation. RESULTS: Mixed-effect models revealed a significant main effect of beverage and positive (but not negative) affective stimuli on subjective strength of craving and significant main effects of both positive and negative affective stimuli on ratings of emotionality. Despite the power to detect relatively small interaction effects, no significant interactions were observed between affect and beverage conditions on any reactivity measure. CONCLUSIONS: A key finding of this study is that positive affective stimuli commonly associated with drinking situations can induce craving in the absence of alcohol cues. Main effects of beverage cue replicated results from previous studies. Beverage and affective cues showed no interaction effects.     

Predictors of postpartum relapse to smoking

Postpartum relapse is common among women who stop smoking during pregnancy. We examined predictors of postpartum relapse in 87 women who quit smoking during pregnancy, 48% of whom relapsed by 6 months postpartum. We also explored the circumstances surrounding their first postpartum cigarette. Multivariate analyses revealed that having more friends/family members who smoke, smoking more heavily pre-pregnancy, and having higher depression scores and less concern about weight at the end of pregnancy were associated with increased risk of relapse postpartum. Most women's first postpartum cigarettes were unplanned, in the presence of another smoker, and while experiencing negative affect. The findings suggest targets for interventions to reduce postpartum relapse.     

Effect of the threat of a disulfiram-ethanol reaction on cue reactivity in alcoholics

Rationale

Little is known about the effect of disulfiram on subjective and autonomic nervous system cue reactivity in the laboratory. The dissuasive psychological effect manifested as a threat would seem to prevail over the pharmacological effect.

Objectives

The primary objective was to determine whether there was a difference in cue reactivity responses during a threat condition compared to a neutral condition during alcohol cue exposure.

Methods

In a crossover randomized study, participants received threat and neutral messages during two cue exposure sessions. The threat condition consisted of leading the patients to believe they had ingested 500 mg of disulfiram and the neutral condition of informing them that they had ingested a placebo, while in both condition they received the same placebo.

Results

Physiological cue reactivity was demonstrated by a decrease in diastolic blood pressure during the threat compared to the neutral condition (p = 0.04). Heart rate and subjective cue reactivity measures remained unchanged. There was a negative affect (assessed by the Positive and Negative Affect Scale) by condition by exposure interaction.

Conclusions

The threat of a disulfiram-ethanol reaction appears to affect cue reactivity physiologically rather than subjectively. While the data does not show changes in subjective ratings, it is possible that there are alternative beneficial effects arising from other cognitive processes that are not captivated by self-reported craving scales, reflected by decreases in negative affect and blood pressure. From this perspective, disulfiram might be recast to be more acceptable to patients.     

The use of nicotine chewing gum as an aid to stopping smoking

Two hundred and ten subjects entered a trial to test the use of a chewing gum containing nicotine as an aid to stopping smoking. They were divided into three groups: nicotine chewing gum, placebo chewing gum, and control. The trial was double blind between the two chewing gum groups. After 1 month the percentage of confirmed non-smokers in the nicotine gum group was 34%, in placebo chewing gum group 37% and the control group 24%. By 6 months most of the non-smokers had relapsed, but the nicotine gum group (23%) was more successful than the placebo (5% or the control group (14%).