Delay of smoking gratification as a laboratory model of relapse: effects of incentives for not smoking, and relationship with measures of executive function

Impulsivity Predicts Relapse—but Not Dropout—in Outpatients with SUD: a Longitudinal Study

The objective of this study was to compare performance on a comprehensive impulsivity battery of SUD outpatients who dropout versus those who do not dropout and of abstainers versus relapsers at 3 and 12 months of treatment follow-up. Impulsivity was measured at the start of treatment and adherence and relapse at 3 and 12 months. The participants are 115 outpatients with SUD. Motor impulsivity (Affective Go/No Go), attentional impulsivity (Stroop), delay discounting (Monetary Choice Questionnaire; MCQ), and decision making (Iowa Gambling Task; IGT) were assessed. Impulsivity was not associated with dropout. There were no relationships between treatment outcomes and the MCQ and IGT. Stroop and affective Go-No Go were associated with relapse at 3 and 12 months. Affective motor disinhibition and cognitive disinhibition predict relapse in outpatients. No cognitive aspect of impulsiveness is related to dropout.

Translational Research in Nicotine Addiction

While commendable strides have been made in reducing smoking initiation and improving smoking cessation rates, current available smoking cessation treatment options are still only mildly efficacious and show substantial interindividual variability in their therapeutic responses. Therefore, the primary goal of preclinical research has been to further the understanding of the neural substrates and genetic influences involved in nicotine's effects and reassess potential drug targets. Pronounced advances have been made by investing in new translational approaches and placing more emphasis on bridging the gap between human and rodent models of dependence. Functional neuroimaging studies have identified key brain structures involved with nicotine-dependence phenotypes such as craving, impulsivity, withdrawal symptoms, and smoking cessation outcomes. Following up with these findings, rodent-modeling techniques have made it possible to dissect the neural circuits involved in these motivated behaviors and ascertain mechanisms underlying nicotine's interactive effects on brain structure and function. Likewise, translational studies investigating single-nucleotide polymorphisms (SNPs) within the cholinergic, dopaminergic, and opioid systems have found high levels of involvement of these neurotransmitter systems in regulating the reinforcing aspects of nicotine in both humans and mouse models. These findings and coordinated efforts between human and rodent studies pave the way for future work determining gene by drug interactions and tailoring treatment options to each individual smoker.

Biometric Data as Real-Time Measure of Physiological Reactions to Environmental Stimuli in the Built Environment

The physiological and cognitive effects of environmental stimuli from the built environment on humans have been studied for more than a century, over short time frames in terms of comfort, and over long-time frames in terms of health and wellbeing. The strong interdependence of objective and subjective factors in these fields of study has traditionally involved the necessity to rely on a number of qualitative sources of information, as self-report variables, which however, raise criticisms concerning their reliability and precision. Recent advancements in sensing technology and data processing methodologies have strongly contributed towards a renewed interest in biometric data as a potential high-precision tool to study the physiological effects of selected stimuli on humans using more objective and real-time measures. Within this context, this review reports on a broader spectrum of available and advanced biosensing techniques used in the fields of building engineering, human physiology, neurology, and psychology. The interaction and interdependence between (i) indoor environmental parameters and (ii) biosignals identifying human physiological response to the environmental stressors are systematically explored. Online databases ScienceDirect, Scopus, MDPI and ResearchGate were scanned to gather all relevant publications in the last 20 years, identifying and listing tools and methods of biometric data collection, assessing the potentials and drawbacks of the most relevant techniques. The review aims to support the introduction of biomedical signals as a tool for understanding the physiological aspects of indoor comfort in the view of achieving an improved balance between human resilience and building resilience, addressing human indoor health as well as energetic and environmental building performance.

Associations Between Smoking Abstinence, Inhibitory Control, and Smoking Behavior: An fMRI Study

Nicotine addiction is associated with dysregulated inhibitory control (IC), mediated by corticothalamic circuitry including the right inferior frontal gyrus (rIFG). Among sated smokers, worse IC task performance and greater IC-related rIFG activity have been shown to be associated with greater relapse vulnerability. The present study investigated the effects of smoking abstinence on associations between IC task performance, rIFG activation, and smoking behavior. Smokers (N = 26, 15 female) completed an IC task (Go/Go/No-go) during fMRI scanning followed by a laboratory-based smoking relapse analog task (SRT) on two visits: once when sated and once following 24 h of smoking abstinence. During the SRT, smokers were provided with monetary rewards for incrementally delaying smoking. A significant main effect of No-go accuracy on latency to smoke during the SRT was observed when collapsing across smoking states (abstinent vs. sated). Similarly, a significant main effect of IC-related activation in rIFG on SRT performance was observed across states. The main effect of state, however, was non-significant in both of these models. Furthermore, the interaction between smoking state and No-go accuracy on SRT performance was non-significant, indicating a similar relationship between IC and lapse vulnerability under both sated and abstinent conditions. The state X rIFG activation interaction on SRT performance was likewise non-significant. Post-hoc whole brain analyses indicated that abstinence resulted in greater IC-related activity in the right middle frontal gyrus (MFG) and insula. Activation during IC in these regions was significantly associated with decreased No-go accuracy. Moreover, greater abstinence induced activity in right MFG during IC was associated with smoking sooner on the SRT. These findings are bolstered by the extant literature on the effects of nicotine on executive function and also contribute novel insights on how individual differences in behavioral and neuroimaging measures of IC may influence relapse propensity independent of smoking state.

Dissociable Effects of Theta-Burst Repeated Transcranial Magnetic Stimulation to the Inferior Frontal Gyrus on Inhibitory Control in Nicotine Addiction

Nicotine addiction, like other substance use disorders (SUD's), is associated with deficits in prefrontal mediated inhibitory control. The strength of inhibitory control task-based functional connectivity (tbFC) between the right inferior frontal gyrus (r.IFG) and thalamus (corticothalamic circuit) mediates the association between successful inhibition and smoking relapse vulnerability. However, the potential efficacy of theta burst stimulation (TBS) to the r.IFG, a treatment known to alter clinical symptoms among neuropsychiatric patients, has not been reported in a SUD population. This study utilized fMRI guided neuronavigation to examine the effects of TBS on inhibitory control among nicotine dependent individuals. Participants (N=12) were scanned while performing an inhibitory control task known to elicit inhibition-related activity in the r.IFG. Using a randomized, counterbalanced cross-over design, participants then received TBS over two visits: excitatory (iTBS) on one visit and inhibitory (cTBS) TBS on the other visit. The effects of each TBS condition on subsequent inhibitory control task performance were examined. A significant condition x time interaction was identified on trials requiring inhibitory control (F (1,10) = 7.27, p = .022, D = 1.63). iTBS improved inhibitory control, whereas cTBS impaired inhibitory control. Brain stimulation did not influence performance in control conditions including novelty detection and response execution. This is the first study to demonstrate that non-invasive neural stimulation using iTBS to the r.IFG enhances baseline inhibitory control among individuals with a SUD. Further research is needed to directly examine the potential parametric effects of TBS on corticothalamic tbFC in individuals with a SUD.

Past and future preference reversals are predicted by delay discounting in smokers and non-smokers

Delay discounting, the devaluation of delayed reinforcers, is one defining behavioral economic characteristic of cigarette smokers. Attempts at abstinence by smokers that result in relapse are conceptualized in this framework as preference reversals. Despite preference reversals being predicted by delay discounting models, little research has investigated the association between discount rate and preference reversals. The present study extended this research by examining the relation between discounting and preference reversals. Because previous research indicates that cigarette smokers discount at higher rates than controls and that past and future discounting are symmetrical, the present study assessed the relation between these two processes when hypothetical money was distanced in the past and future, respectively. These assessments of delay discounting and preference reversals were adapted from Yi, Matusiewicz, and Tyson (2016) and examined in 68 smokers and 68 nonsmokers using the crowdsourcing program Amazon Mechanical Turk. Smokers discounted both past and future hypothetical money more steeply than demographically matched controls. Smokers switched preference from the smaller-sooner (SS) to the larger-later (LL) outcome more slowly than nonsmokers, consistent with smokers' steeper delay discounting. For each group, significant positive correlations between past and future discount rates and past and future preference reversals was obtained. The overall pattern of results illustrate symmetry between past and future discounting and preference reversals, respectively and that discount rate is positively associated with the timing of preference reversals. Importantly, the results confirm that cigarette smokers discount more and reverse preference from a SS to a LL reward later than controls. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Experimental reductions of delay discounting and impulsive choice: A systematic review and meta-analysis

Many behaviors posing significant risks to public health are characterized by repeated decisions to forego better long-term outcomes in the face of immediate temptations. Steeply discounting the value of delayed outcomes often underlies a pattern of impulsive choice. Steep delay discounting is correlated with addictions (e.g., substance abuse, obesity) and behaviors such as seatbelt use and risky sexual activity. As evidence accumulates suggesting steep delay discounting plays a causal role in these maladaptive behaviors, researchers have begun testing methods for reducing discounting. In this first systematic and comprehensive review of this literature, the findings of 92 articles employing different methodologies to reduce discounting are evaluated narratively and meta-analytically. Although most of the methods reviewed produced significant reductions in discounting, they varied in effect sizes. Most methods were ideal for influencing one-off choices (e.g., framing and priming manipulations), although other successful manipulations, such as episodic future thinking, could be incorporated into existing therapies designed to produce longer-lasting changes in decision-making. The largest and longest-lasting effects were produced by learning-based manipulations, although translational research is needed to determine the generality and clinical utility of these methods. Methodological shortcomings in the existing literature and suggestions for ameliorating these issues are discussed. This review reveals a variety of methods with translational potential, which, through continued refinement, may prove effective in reducing impulsive choice and its associated maladaptive decisions that negatively impact quality of life. (PsycINFO Database Record

Clinical models of decision making in addiction

As research on decision making in addiction accumulates, it is increasingly clear that decision-making processes are dysfunctional in addiction and that this dysfunction may be fundamental to the initiation and maintenance of addictive behavior. How drug-dependent individuals value and choose among drug and nondrug rewards is consistently different from non-dependent individuals. The present review focuses on the assessment of decision-making in addiction. We cover the common behavioral tasks that have shown to be fruitful in decision-making research and highlight analytical and graphical considerations, when available, to facilitate comparisons within and among studies. Delay discounting tasks, drug demand tasks, drug choice tasks, the Iowa Gambling Task, and the Balloon Analogue Risk Task are included.

Toward a laboratory model for psychotherapeutic treatment screening: Implementation intentions and incentives for abstinence in an analog of smoking relapse

Despite reductions in cigarette smoking in the United States, approximately 40 million Americans are smokers. Innovative interventions are needed to help remaining smokers quit. To develop innovative interventions, precise and effective tools are needed. Here, a laboratory model of smoking relapse is assessed for its ability to detect increased resistance to smoking across 2 interventions and for its sensitivity to differing degrees of effectiveness. Nicotine-deprived participants (N = 36) completed, in randomized order, 4 smoking resistance sessions with and without implementation intentions and monetary incentives. A Cox proportional hazard mixed-effects model indicated significant differences between condition, χ²(3) = 64.87, p < .001, and the Questionnaire on Smoking Urges, χ²(1) = 4.86, p = .03. Comparisons between conditions were used to estimate the effect size of each condition on delay to smoking reinitiation. The implementation intentions intervention had a small effect (d = 0.32), the monetary incentives had a large effect (d = 0.89) and the combination of both interventions had a large effect size (d = 1.20). This initial investigation of the smoking resistance paradigm showed sensitivity to smoking reinitiation across intervention conditions. Individuals resisted smoking significantly more in the presence of monetary incentives and implementation intentions than without these interventions. These results provide support for further examination of these interventions in more translational settings and the use of this laboratory analog to screen future interventions and treatment packages. (PsycINFO Database Record

Executive function fails to predict smoking outcomes in a clinical trial to motivate smokers to quit

BACKGROUND

Executive function (EF) is considered an important mediator of health outcomes. It is hypothesized that those with better EF are more likely to succeed in turning their intentions into actual health behaviors. Prior studies indicate EF is associated with smoking cessation. Experimental and longitudinal studies, however, have yielded mixed results. Few studies have examined whether EF predicts post-treatment smoking behavior. Fewer still have done so prospectively in a large trial. We sought to determine if EF predicts quit attempts and cessation among community smokers in a large randomized trial evaluating the efficacy of motivational interventions for encouraging cessation.

METHODS

Participants (N=255) completed a baseline assessment that included a cognitive battery to assess EF (Oral Trail Making Test B, Stroop, Controlled Oral Word Association Test). Participants were then randomized to 4 sessions of Motivational Interviewing or Health Education or one session of Brief Advice to quit. Quit attempts and cessation were assessed at weeks 12 and 26.

RESULTS

In regression analyses, none of the EF measures were statistically significant predictors of quit attempts or cessation (all ps>0.20).

CONCLUSIONS

Our data did not support models of health behavior that emphasize EF as a mediator of health outcomes. Methodological shortcomings weaken the existing support for an association between EF and smoking behavior. We suggest methodological improvements that could help move this potentially important area of research forward.

Impact of Different e-Cigarette Generation and Models on Cognitive Performances, Craving and Gesture: A Randomized Cross-Over Trial (CogEcig)

Introduction: Most electronic-cigarettes (e-cigarette) are designed to look like traditional cigarettes and simulate the visual, sensory, and behavioral aspects of smoking traditional cigarettes. This research aimed to explore whether different e-cigarette models and smokers' usual classic cigarettes can impact on cognitive performances, craving and gesture.

Methods: The study is randomized cross-over trial designed to compare cognitive performances, craving, and gesture in subjects who used first generation electronic cigarettes, second generation electronic cigarettes with their usual cigarettes. (Trial registration: ClinicalTrials.gov number NCT01735487).

Results: Cognitive performance was not affected by “group condition.” Within-group repeated measures analyses showed a significant time effect, indicating an increase of participants' current craving measure in group “usual classic cigarettes (group C),” “disposable cigalike electronic cigarette loaded with cartridges with 24 mg nicotine (group H), second generation electronic cigarette, personal vaporizer model Ego C, loaded with liquid nicotine 24 mg (group E). Measures of gesture not differ over the course of the experiment for all the products under investigation

Conclusion: All cognitive measures attention, executive function and working memory are not influenced by the different e-cigarette and gender showing that in general electronics cigarettes could become a strong support also from a cognitive point of view for those who decide to quit smoking. It seems that not only craving and other smoke withdrawal symptoms but also cognitive performance is not only linked to the presence of nicotine; this suggests that the reasons behind the dependence and the related difficulty to quit smoking needs to be looked into also other factors like the gesture.

Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT01735487.

Financial Incentives for Reducing Smoking and Promoting Other Health-Related Behavior Change in Vulnerable Populations

Substantial reductions in U.S. cigarette smoking and associated chronic diseases over the past 50 years have benefited health. Unfortunately, those reductions have distributed unevenly throughout the population. Smoking remains prevalent and even increasing among certain vulnerable populations: economically disadvantaged groups, those with other substance-use disorders or mental illness, certain ethnic and racial minorities, and gender and sexual minorities. Moreover, other unhealthy behavior patterns (physical inactivity, unhealthy food choices, risky sexual behavior, poor adherence to medical preventive regimens) and associated chronic diseases are also overrepresented in many of these same populations. Disparities in unhealthy behavior patterns contribute to health disparities and escalating health care costs, underscoring the need for more effective behavior-change strategies. This report reviews research on the efficacy of financial incentives for reducing smoking in vulnerable populations, while also touching on applications of that behavior-change strategy for promoting other health-related behavior changes in vulnerable populations.

The involvement of the striatum in decision making

Decision making has been extensively studied in the context of economics and from a group perspective, but still little is known on individual decision making. Here we discuss the different cognitive processes involved in decision making and its associated neural substrates. The putative conductors in decision making appear to be the prefrontal cortex and the striatum. Impaired decision-making skills in various clinical populations have been associated with activity in the prefrontal cortex and in the striatum. We highlight the importance of strengthening the degree of integration of both cognitive and neural substrates in order to further our understanding of decision-making skills. In terms of cognitive paradigms, there is a need to improve the ecological value of experimental tasks that assess decision making in various contexts and with rewards; this would help translate laboratory learnings into real-life benefits. In terms of neural substrates, the use of neuroimaging techniques helps characterize the neural networks associated with decision making; more recently, ways to modulate brain activity, such as in the prefrontal cortex and connected regions (eg, striatum), with noninvasive brain stimulation have also shed light on the neural and cognitive substrates of decision making. Together, these cognitive and neural approaches might be useful for patients with impaired decision-making skills. The drive behind this line of work is that decision-making abilities underlie important aspects of wellness, health, security, and financial and social choices in our daily lives.

Can repetitive mental simulation of smoking engender habituation?

Smoking cue exposure sensitizes smokers to cigarettes (i.e., increases cravings). Research examining the overlap between perception and mental imagery suggests that mentally simulating smoking a cigarette in a manner analogous to actually smoking should lead to habituation or a decrease in a smoker's motivation to smoke. The authors sought to determine whether repetitive mental simulation of smoking can engender habituation thereby reducing smoking cue-induced craving and shifts in mood, latency to smoke, and the hedonic response to smoking. These hypotheses were tested in nontreatment seeking smokers (n = 61; 24 women/37 men) ages 18-55 years old, who were not incentivized to quit. The authors used a 2 (in vivo cue: smoking, neutral) × 2 (imagery: repetitive, limited) within-subjects design. Results revealed that repetitive imagery altered the effect of cue type for negative mood and subjective cigarette reward as evidenced by significant Imagery × Cue interactions. Repetitive imagery after a smoking cue reduced negative mood more than limited imagery (β = -1.19, p = .004). Repetitive imagery also reduced the reward derived from smoking a cigarette more than limited imagery (β = -.41, p < .0001). Only main effects of cue type on craving (β = 3.39, p = .01) and positive mood (β = -1.18, p = .03) were found. Greater imagery strength predicted a longer latency to smoke (β = .76, p = .001). Cognitive strategies that directly engage cue-induced craving through repetitive smoking imagery may reduce smoking cue-induced increases in negative mood and reward from a cigarette lapse potentially preventing smoking relapse. (PsycINFO Database Record

The impact of flavoring on the rewarding and reinforcing value of e-cigarettes with nicotine among young adult smokers

OBJECTIVE

Flavored e-cigarette use has risen rapidly, especially among young adults who also smoke cigarettes. We sought to determine whether flavoring enhances the subjective rewarding value, relative reinforcing value, and absolute reinforcing value of an e-cigarette with nicotine compared to an unflavored e-cigarette with nicotine.

METHODS

Using a within-subjects design, young adult smokers (n=32) participated in three human laboratory sessions. Session 1 evaluated the rewarding value of flavoring by having participants rate unflavored and flavored e-cigarettes with nicotine. Session 2 assessed the relative reinforcing value of a flavored vs unflavored e-cigarette via a choice task that evaluated the willingness to "work" to hit targets on a computer screen to earn flavored or unflavored e-cigarette puffs. Session 3 measured the absolute reinforcing value of flavored versus unflavored e-cigarettes via a 90-min ad-libitum vaping session where puffs from each e-cigarette were counted.

RESULTS

Subjective reward value was higher for the flavored versus the unflavored e-cigarette (β=0.83, CI 0.35-1.32, p=0.001). Participants worked harder for flavored e-cigarette puffs versus unflavored e-cigarette puffs (breakpoint=5.7; 597 responses versus 127 responses; β=460.733, CI 246.58-674.88, p<0.0001). Participants took twice as many flavored puffs than unflavored e-cigarette puffs (40 vs 23 puffs; IRR=2.028, CI 1.183-3.475, p=0.01).

CONCLUSIONS

Flavoring enhances the rewarding and reinforcing value of e-cigarettes with nicotine, and thus their abuse liability in young adult smokers. Further research is necessary to determine whether the use of flavoring in e-cigarettes impacts cigarette smoking behavior among young adults.

Reliability and validity of measures of impulsive choice and impulsive action in smokers trying to quit

Cross-sectional research suggests that smokers are more impulsive than are nonsmokers, but few studies have examined relations between impulsiveness and later success in quitting smoking. The purpose of this study was to investigate the reliability and predictive validity of facets of impulsiveness in adult smokers trying to quit. Baseline behavioral measures of impulsive choice (assessed with a delay discounting task) and impulsive action (assessed with a measure of behavioral disinhibition) were used as predictors of smoking cessation success over 12 weeks. The sample included 116 adult (18 years old or older) daily smokers from central New Jersey. Impulsive choice, impulsive action, and self-reported impulsiveness were not significantly related to one another at baseline. Impulsive choice had high test-retest reliability from pre- to postquit, whereas impulsive action was less stable. Test-retest reliability from prequit to 3 weeks' postquit was moderated by achievement of 7-day abstinence. Baseline impulsive action was significantly negatively related to quitting for at least 1 day in the first 2 weeks of a quit attempt and of prolonged abstinence (no relapse over the next 10 weeks). Baseline impulsive choice was robustly associated with biochemically verified 7-day point-prevalence abstinence 12 weeks' postquit, such that those with lower delay discounting were more likely to achieve abstinence. Facets of impulsiveness appear to function largely independently in adult smokers, as indicated by their lack of intercorrelation, differential stability, and differential relations with abstinence. Impulsive action may impede initial quitting, whereas impulsive choice may be an obstacle to maintaining lasting abstinence.

Delay Discounting and Preference Reversals by Cigarette Smokers

Quit attempts made by smokers that result in relapse to smoking are conceptualized in behavioral economics as preference reversals, in which preference for a larger-later outcome switches to preference for a smaller-sooner outcome. Though preference reversals are predicted by models of delay discounting, we are aware of no human research that has explicitly established that rate of delay discounting is associated with preference reversals. The present study attempted to establish this connection. Assessments of delay discounting of hypothetical money rewards at two magnitudes ($50, $1000) were examined from forty-five smokers, as well as a novel preference reversal task designed to determine when a preference reversal would occur for the same amounts of hypothetical money. Results from the preference reversal task were used to classify participants as predicted high, moderate, and low discounters, and rates of delay discounting were compared between these classifications at each magnitude. Statistically significant differences were observed between predicted high and low discounters in both magnitude conditions, and between predicted high and moderate discounters in the $1000 magnitude condition. Correlations between delay discounting and preference reversal amongst moderate discounters, though in the predicted direction, did not reach statistical significance. The overall pattern of results are consistent with the indication that rate of delay discounting is associated with the timing of preference reversals.

Discounting of qualitatively different delayed health outcomes in current and never smokers

In delay discounting, temporally remote outcomes have less value. Cigarette smoking is associated with steeper discounting of money and consumable outcomes. It is presently unclear whether smokers discount health outcomes more than nonsmokers. We sought to establish the generality of steep discounting for different types of health outcomes in cigarette smokers. Seventy participants (38 smokers and 32 nonsmokers) completed 4 hypothetical outcome delay-discounting tasks: a gain of $500, a loss of $500, a temporary boost in health, and temporary cure from a debilitating disease. Participants reported the duration of each health outcome that would be equivalent to $500; these durations were then used in the respective discounting tasks. Delays ranged from 1 week to 25 years. Smokers' indifference points for monetary gains, boosts in health, and temporary cures were lower than indifference points from nonsmokers. Indifference points of 1 outcome were correlated with indifference points of other outcomes. Smokers demonstrate steeper discounting across a range of delayed outcomes. How a person discounts 1 outcome predicts how they will discount other outcomes. These 2 findings support our assertion that delay discounting is in part a trait.

Reinforcing value of smoking relative to physical activity and the effects of physical activity on smoking abstinence symptoms among young adults

This study sought to evaluate whether individual differences in the reinforcing value of smoking relative to physical activity (RRVS) moderated the effects of physical activity on smoking abstinence symptoms in young adult smokers. The repeated-measures within-subjects design included daily smokers (N = 79) 18-26 years old. RRVS was measured with a validated behavioral choice task. On 2 subsequent visits, participants completed self-report measures of craving, withdrawal, mood, and affective valence before and after they engaged in passive sitting or a bout of physical activity. RRVS did not moderate any effects of physical activity (ps > .05). Physical activity compared with passive sitting predicted decreased withdrawal symptoms, β = -5.23, 95% confidence interval (CI) [-6.93, -3.52] (p < .001), negative mood, β = -2.92, 95% CI [-4.13, -1.72] (p < .001), and urge to smoke. β = -7.13, 95% CI [-9.39, -4.86] (p < .001). Also, physical activity compared with passive sitting predicted increased positive affect, β = 3.08, 95% CI [1.87, 4.28] (p < .001) and pleasurable feelings, β = 1.07, 95% CI [0.58, 1.55] (p < .001), and greater time to first cigarette during the ad libitum smoking period, β = 211.76, 95% CI [32.54, 390.98] (p = .02). RRVS predicted higher levels of pleasurable feelings, β = 0.22, 95% CI [0.01, 0.43] (p = .045), increased odds of smoking versus remaining abstinent during the ad libitum smoking period, β = 0.04, 95% CI [0.01, 0.08] (p = .02), and reduced time to first cigarette, β = -163.00, 95% CI [-323.50, -2.49] (p = .047). Regardless of the RRVS, physical activity produced effects that may aid smoking cessation in young adult smokers. However, young adult smokers who have a higher RRVS will be less likely to choose to engage physical activity, especially when smoking is an alternative.

Nicotine deprivation, temporal discounting and choice consistency in heavy smokers

The subjective value of rewards declines the longer rewards are delayed into the future ("delay discounting"). Discounting behavior varies both as a function of an individual's trait and current state. The degree of discounting has repeatedly been associated with relapse following treatment of addiction. Therefore, the effects of acute drug deprivation on discounting processes are potentially of high clinical relevance. In two testing sessions (24 hr of nicotine deprivation vs. normal smoking) 37 heavy smoking participants made choices between immediate and delayed rewards as well as between shorter and longer delayed rewards. We found no evidence for an effect of nicotine deprivation on delay discounting of potentially real monetary rewards in both types of decision tasks. Although choice stochasticity was numerically increased after deprivation, this effect was not significant (p>.1). Participants responded significantly slower after nicotine deprivation. Our study supports previous findings that choice impulsivity as measured using discounting tasks is not affected by nicotine deprivation, at least not if real monetary rewards of lower amounts are at stake.

Delay discounting of hypothetical monetary rewards with decoys

The current research attempted to decrease individuals' rates of delay discounting by introducing decoys that are similar but inferior to delayed rewards. Two experiments in the current study compared patterns of delay discounting generated by repeated choices between two hypothetical monetary rewards in the absence or presence of a decoy. Binary questionnaires (i.e., decoy absent) included questions with two options: a smaller-sooner (SS) reward and a larger-later (LL) reward. Trinary questionnaires (i.e., decoy present) included questions with three options: an SS reward, an LL reward, and a decoy. If an option is at least as rewarding on every dimension of value as an alternative and the option is more rewarding than an alternative on at least one dimension, then the option is considered to dominate the alternative (Wedell, 1991). The first experiment assessed the influence of decoys dominated by LL rewards (LL(-) decoys), which were constructed to be similar (on the dimension of amount) but inferior (on the dimension of delay) to LL rewards. The second experiment examined the effects of counterbalancing the order of binary and trinary questionnaires. In the first experiment, participants discounted to a lesser degree when LL(-) decoys were present as compared to when they were absent. In the second experiment, participants only discounted to a lesser degree on trinary questionnaires with LL(-) decoys when they had not previously completed binary questionnaires. Patterns of discounting generated by binary questionnaires were similar to those generated by trinary questionnaires when decoys are present; however, the degree to which individuals discounted delayed rewards was affected by the number of and type of options that were available. The current results join previous evidence suggesting that rates of delay discounting are sensitive to a variety of contextual influences.

Predictors of delay discounting among smokers: education level and a Utility Measure of Cigarette Reinforcement Efficacy are better predictors than demographics, smoking characteristics, executive functioning, impulsivity, or time perception

Ninety-four smokers completed the delay discounting procedure for either hypothetical amounts of money, $10 (money) and $1000 (money) or hypothetical amounts of cigarettes ($10 and $1000 worth of cigarettes). We investigated how variables previously found to be related to rates of delay discounting accounted for the observed results. These variables included the following: demographic information, smoking characteristics, executive function abilities, impulsivity, time perception, and the Utility Measure of Cigarette Reinforcing Efficacy (UMCE). Education level and UMCE were each significantly correlated with 3 out of 4 of the discounting measures. Moreover, the largest effect sizes observed were between these two measures and the four discounting measures. All potential discounting predictors were also investigated using step-wise linear regression with Bayesian Information Criterion (BIC) analysis—these BIC models revealed that education level and UMCE accounted for large portions of the variance. We conclude that education level and UMCE were the most consistent predictors of discounting. This data is discussed within the framework of a widely accepted neuroeconomic model that suggests that two brain systems separately assess two separate facets of decision-making, and the interplay between these two systems determines self-control in smokers. We hypothesize that education level and UMCE may serve as surrogate measures of the functionality of these two systems and that discounting may be a sentinel measure of self-control.

Does impulsiveness moderate response to financial incentives for smoking cessation among pregnant and newly postpartum women?

We examined whether impulsiveness moderates response to financial incentives for cessation among pregnant smokers. Participants were randomized to receive financial incentives delivered contingent on smoking abstinence or to a control condition wherein incentives were delivered independent of smoking status. The study was conducted in two steps: First, we examined associations between baseline impulsiveness and abstinence at late pregnancy and 24-weeks-postpartum as part of a planned prospective study of this topic using data from a recently completed, randomized controlled clinical trial (N = 118). Next, to increase statistical power, we conducted a second analysis collapsing results across that recent trial and two prior trials involving the same study conditions (N = 236). Impulsivity was assessed using a delay discounting (DD) of hypothetical monetary rewards task in all three trials and Barratt Impulsiveness Scale (BIS) in the most recent trial. Neither DD nor BIS predicted smoking status in the single or combined trials. Receiving abstinence-contingent incentives, lower baseline smoking rate, and a history of quit attempts prepregnancy predicted greater odds of antepartum abstinence across the single and combined trials. No variable predicted postpartum abstinence across the single and combined trials, although a history of antepartum quit attempts and receiving abstinence-contingent incentives predicted in the single and combined trials, respectively. Overall, this study provides no evidence that impulsiveness as assessed by DD or BIS moderates response to this treatment approach while underscoring a substantial association of smoking rate and prior quit attempts with abstinence across the contingent incentives and control treatment conditions.

Low Dopamine D2/D3 Receptor Availability is Associated with Steep Discounting of Delayed Rewards in Methamphetamine Dependence

BACKGROUND

Individuals with substance use disorders typically exhibit a predilection toward instant gratification with apparent disregard for the future consequences of their actions. Indirect evidence suggests that low dopamine D2-type receptor availability in the striatum contributes to the propensity of these individuals to sacrifice long-term goals for short-term gain; however, this possibility has not been tested directly. We investigated whether striatal D2/D3 receptor availability is negatively correlated with the preference for smaller, more immediate rewards over larger, delayed alternatives among research participants who met DSM-IV criteria for methamphetamine (MA) dependence.

METHODS

Fifty-four adults (n = 27 each: MA-dependent, non-user controls) completed the Kirby Monetary Choice Questionnaire, and underwent positron emission tomography scanning with [(18)F]fallypride.

RESULTS

MA users displayed steeper temporal discounting (p = 0.030) and lower striatal D2/D3 receptor availability (p < 0.0005) than controls. Discount rate was negatively correlated with striatal D2/D3 receptor availability, with the relationship reaching statistical significance in the combined sample (r = -0.291, p = 0.016) and among MA users alone (r = -0.342, p = 0.041), but not among controls alone (r = -0.179, p = 0.185); the slopes did not differ significantly between MA users and controls (p = 0.5).

CONCLUSIONS

These results provide the first direct evidence of a link between deficient D2/D3 receptor availability and steep temporal discounting. This finding fits with reports that low striatal D2/D3 receptor availability is associated with a higher risk of relapse among stimulant users, and may help to explain why some individuals choose to continue using drugs despite knowledge of their eventual negative consequences. Future research directions and therapeutic implications are discussed.

Psychological symptoms, smoking lapse behavior, and the mediating effects of nicotine withdrawal symptoms: A laboratory study

The influence of psychological symptoms on smoking-lapse behavior is critical to understand. However, this relationship is obscured by comorbidity across multiple forms of psychological symptoms and their overlap with nicotine withdrawal. To address these challenges, we constructed a structural model of latent factors underlying 9 manifest scales of affective and behavioral symptoms and tested relations between latent factors and manifest scale residuals with nicotine withdrawal and smoking lapse in a laboratory analog task. Adult daily smokers (N = 286) completed a baseline session at which several forms of affective and behavioral symptoms were assessed and 2 experimental sessions (i.e., following 16 hr of smoking abstinence and following regular smoking), during which withdrawal symptoms and delay of smoking in exchange for monetary reinforcement, as an analogue for lapse propensity, were measured. A single second-order factor of general psychological maladjustment associated with more severe withdrawal-like symptoms, which in turn associated with shorter delay of smoking. The first-order factors, which tapped qualitatively unique domains of psychological symptoms (low positive affect, negative affect, disinhibition), and the manifest scale residuals provided little predictive power beyond the second-order factor with regard to lapse behavior. Relations among general psychological maladjustment, withdrawal-like symptoms, and lapse were significant in both abstinent and nonabstinent conditions, suggesting that psychological maladjustment, and not nicotine withdrawal per se, accounted for the relation with lapse. These results highlight the potential for smoking-cessation strategies that target general psychological maladjustment processes and have implications for addressing withdrawal-like symptoms among individuals with psychological symptoms.

Temperament and impulsivity predictors of smoking cessation outcomes

AIMS

Temperament and impulsivity are powerful predictors of addiction treatment outcomes. However, a comprehensive assessment of these features has not been examined in relation to smoking cessation outcomes.

METHODS

Naturalistic prospective study. Treatment-seeking smokers (n = 140) were recruited as they engaged in an occupational health clinic providing smoking cessation treatment between 2009 and 2013. Participants were assessed at baseline with measures of temperament (Temperament and Character Inventory), trait impulsivity (Barratt Impulsivity Scale), and cognitive impulsivity (Go/No Go, Delay Discounting and Iowa Gambling Task). The outcome measure was treatment status, coded as "dropout" versus "relapse" versus "abstinence" at 3, 6, and 12 months endpoints. Participants were telephonically contacted and reminded of follow-up face to face assessments at each endpoint. The participants that failed to answer the phone calls or self-reported discontinuation of treatment and failed to attend the upcoming follow-up session were coded as dropouts. The participants that self-reported continuing treatment, and successfully attended the upcoming follow-up session were coded as either "relapse" or "abstinence", based on the results of smoking behavior self-reports cross-validated with co-oximetry hemoglobin levels. Multinomial regression models were conducted to test whether temperament and impulsivity measures predicted dropout and relapse relative to abstinence outcomes.

RESULTS

Higher scores on temperament dimensions of novelty seeking and reward dependence predicted poorer retention across endpoints, whereas only higher scores on persistence predicted greater relapse. Higher scores on the trait dimension of non-planning impulsivity but not performance on cognitive impulsivity predicted poorer retention. Higher non-planning impulsivity and poorer performance in the Iowa Gambling Task predicted greater relapse at 3 and 6 months and 6 months respectively.

CONCLUSION

Temperament measures, and specifically novelty seeking and reward dependence, predict smoking cessation treatment retention, whereas persistence, non-planning impulsivity and poor decision-making predict smoking relapse.

Impulsivity and cigarette smoking: discounting of monetary and consumable outcomes in current and non-smokers

RATIONALE

In delay discounting, temporally remote rewards have less value. Cigarette smoking is associated with steeper discounting of delayed money. The generality of this to nonmonetary outcomes, however, is unknown.

OBJECTIVES

We sought to determine whether cigarette smokers also show steep discounting of other delayed outcomes.

METHODS

Sixty-five participants (32 smokers and 33 non-smokers) completed four delay-discounting tasks, each involving different hypothetical outcomes. In the monetary task, participants indicated their preference for a smaller amount of money available immediately (titrated across trials) and $100 awarded at delays ranging from 1 week to 25 years (tested in blocks). In the three other discounting tasks the larger-later reward was $100 worth of a favorite food, alcoholic drink, or a favorite form of entertainment. All other aspects of these discounting tasks were identical to the monetary discounting task.

RESULTS

As previously shown, smokers discounted delayed money more steeply than non-smokers did. In addition, smokers discounted delayed food and entertainment rewards more steeply than did nonsmokers. A person's discounting of one outcome was correlated with discounting of other outcomes. Non-smokers discounted money less steeply than all other outcomes; smokers discounted money significantly less than food.

CONCLUSIONS

When compared to nonsmokers, cigarette smokers more steeply discount several types of delayed outcomes. This result, together with the finding that cross-commodity discounting rates were correlated within subjects, suggests that delay discounting is a trait that extends across domains.

Weak ventral striatal responses to monetary outcomes predict an unwillingness to resist cigarette smoking

As a group, cigarette smokers exhibit blunted subjective, behavioral, and neurobiological responses to nondrug incentives and rewards, relative to nonsmokers. Findings from recent studies suggest, however, that there are large individual differences in the devaluation of nondrug rewards among smokers. Moreover, this variability appears to have significant clinical implications, since reduced sensitivity to nondrug rewards is associated with poorer smoking cessation outcomes. Currently, little is known about the neurobiological mechanisms that underlie these individual differences in the responsiveness to nondrug rewards. Here, we tested the hypothesis that individual variability in reward devaluation among smokers is linked to the functioning of the striatum. Specifically, functional magnetic resonance imaging was used to examine variability in the neural response to monetary outcomes in nicotine-deprived smokers anticipating an opportunity to smoke-circumstances found to heighten the devaluation of nondrug rewards by smokers in prior work. We also investigated whether individual differences in reward-related brain activity in those expecting to have access to cigarettes were associated with the degree to which the same individuals subsequently were willing to resist smoking in order to earn additional money. Our key finding was that deprived smokers who exhibited the weakest response to rewards (i.e., monetary gains) in the ventral striatum were least willing to refrain from smoking for monetary reinforcement. These results provide evidence that outcome-related signals in the ventral striatum serve as a marker for clinically meaningful individual differences in reward-motivated behavior among nicotine-deprived smokers.

A laboratory-based evaluation of exercise plus contingency management for reducing cigarette smoking

BACKGROUND

Both contingency management (CM) and exercise have shown promise as smoking cessation treatments, but their combined effects have not been evaluated. The present study evaluated whether CM (in which motivational incentives are provided for abstinence) plus exercise reduced smoking more than either component alone.

METHOD

In a within-subjects design, 20 smokers were exposed to exercise plus CM, exercise plus CM-control (non-contingent incentives), inactivity plus CM, and inactivity plus CM-control.

RESULTS

CM increased latencies to smoke and decreased total puffs (Mdns = 39.6 min and .8 puffs, respectively) relative to CM-control (Mdns = 2.5 min and 12.8 puffs). Exercise decreased craving relative to baseline for craving based on both the pleasurable consequences of smoking (D=-10.7 on a 100-point visual analog scale) and anticipated relief from withdrawal (D=-5.9), whereas inactivity increased both components of craving (Ds=7.6 and 3.5). Exercise had no effect on smoking or a measure of temporal discounting.

CONCLUSIONS

Although exercise decreased craving, it did not affect smoking behavior. Exercise plus CM was not more effective than CM alone.

The role of impulsivity in dropout from treatment for cigarette smoking

Impulsivity is a variable that has been associated with drug use. This study analyzes impulsivity from two different paradigms, one considering it as a trait and the other based on its behavioral correlates, such as disinhibition and impulsive decision-making in the treatment prognosis (maintain abstinence, relapse and dropout) of smokers after outpatient treatment. The participants in the study were 113 smokers who requested treatment for nicotine addiction. They were assigned to three groups according to whether or not they remained abstinent one month after beginning treatment; thus, group 1 was abstinent, group 2 had relapsed, and group 3 had dropped out of treatment. The participants filled out the Semi-structured Interview for Smokers, the Fargerström Test for Nicotine Dependence, the Temperament and Character Inventory-Revised (TCI-R) and the Delay Discounting Task (DDT). The Delay Discounting variable presents lower scores in the dropout group than in the relapse and abstinent groups, with the highest scores in the relapse group. Differences were also found on the Harm Avoidance (HA) variable, with lower scores in the dropout group compared to the relapse group. The importance of these results lies in the consideration of the smoker's personality profile in order to prevent both dropout and relapse.

Decreased delay discounting in former cigarette smokers at one year after treatment

Current cigarette smokers exhibit greater delay discounting relative to ex-smokers. However, few studies have assessed longitudinal changes in delay discounting and cigarette smoking. The purpose of this study was to assess changes in delay discounting of hypothetical monetary rewards and smoking among treatment-seeking smokers (N=80) at baseline, after 6 weeks of behavioral treatment, and at 12-month follow-up. Results showed no changes in delay discounting in either smokers or abstainers at the end-of-treatment. In contrast, at 12-month follow-up, significant decreases in delay discounting were observed in abstainers while delay discounting remained the same for smokers. To our knowledge, this is the first study to observe significant decreases in delay discounting following prolonged smoking abstinence. Such findings provide evidence that delay discounting may have more state-like characteristics than previously believed.

Does temporal discounting explain unhealthy behavior? A systematic review and reinforcement learning perspective

The tendency to make unhealthy choices is hypothesized to be related to an individual's temporal discount rate, the theoretical rate at which they devalue delayed rewards. Furthermore, a particular form of temporal discounting, hyperbolic discounting, has been proposed to explain why unhealthy behavior can occur despite healthy intentions. We examine these two hypotheses in turn. We first systematically review studies which investigate whether discount rates can predict unhealthy behavior. These studies reveal that high discount rates for money (and in some instances food or drug rewards) are associated with several unhealthy behaviors and markers of health status, establishing discounting as a promising predictive measure. We secondly examine whether intention-incongruent unhealthy actions are consistent with hyperbolic discounting. We conclude that intention-incongruent actions are often triggered by environmental cues or changes in motivational state, whose effects are not parameterized by hyperbolic discounting. We propose a framework for understanding these state-based effects in terms of the interplay of two distinct reinforcement learning mechanisms: a “model-based” (or goal-directed) system and a “model-free” (or habitual) system. Under this framework, while discounting of delayed health may contribute to the initiation of unhealthy behavior, with repetition, many unhealthy behaviors become habitual; if health goals then change, habitual behavior can still arise in response to environmental cues. We propose that the burgeoning development of computational models of these processes will permit further identification of health decision-making phenotypes.

Impulsivity as a vulnerability factor for poor addiction treatment outcomes: a review of neurocognitive findings among individuals with substance use disorders

With the current review, we explore the hypothesis that individual differences in neurocognitive aspects of impulsivity (i.e., cognitive and motor disinhibition, delay discounting and impulsive decision-making) among individuals with a substance use disorder are linked to unfavorable addiction treatment outcomes, including high drop-out rates and difficulties in achieving and maintaining abstinence. A systematic review of the literature was carried out using PubMed, PsycINFO and Web of Knowledge searches. Twenty-five unique empirical papers were identified and findings were considered in relation to the different impulsivity dimensions. Although conceptual/methodological heterogeneity and lack of replication are key limitations of studies in this area, findings speak for a prominent role of cognitive disinhibition, delay discounting and impulsive decision-making in the ability to successfully achieve and maintain abstinence during and following addiction treatment. In contrast, indices of motor disinhibition appear to be unrelated to abstinence levels. Whereas the relationship between impulsivity and treatment retention needs to be examined more extensively, preliminary evidence suggests that impulsive/risky decision-making is unrelated to premature treatment drop-out among individuals with a substance use disorder. The reviewed findings are discussed in terms of their clinical implications.

An efficient early phase 2 procedure to screen medications for efficacy in smoking cessation

RATIONALE

Initial screening of new medications for potential efficacy (i.e., Food and Drug Administration (FDA) early phase 2), such as in aiding smoking cessation, should be efficient in identifying which drugs do, or do not, warrant more extensive (and expensive) clinical testing.

OBJECTIVES

This focused review outlines our research on development, evaluation, and validation of an efficient crossover procedure for sensitivity in detecting medication efficacy for smoking cessation. First-line FDA-approved medications of nicotine patch, varenicline, and bupropion were tested as model drugs, in three separate placebo-controlled studies. We also tested specificity of our procedure in identifying a drug that lacks efficacy, using modafinil.

RESULTS

This crossover procedure showed sensitivity (increased days of abstinence) during week-long "practice" quit attempts with each of the active cessation medications (positive controls) versus placebo, but not with modafinil (negative control) versus placebo, as hypothesized. Sensitivity to medication efficacy signal was observed only in smokers high in intrinsic quit motivation (i.e., already preparing to quit soon) and not smokers low in intrinsic quit motivation, even if monetarily reinforced for abstinence (i.e., given extrinsic motivation).

CONCLUSIONS

A crossover procedure requiring less time and fewer subjects than formal trials may provide an efficient strategy for a go/no-go decision whether to advance to subsequent phase 2 randomized clinical trials with a novel drug. Future research is needed to replicate our results and evaluate this procedure with novel compounds, identify factors that may limit its utility, and evaluate its applicability to testing efficacy of compounds for treating other forms of addiction.

Impulsivity and substance-related attentional bias: a meta-analytic review

BACKGROUND

Previous research demonstrates the role of attentional bias in addictive behaviors. Impulsivity is thought to affect the strength of attentional biases, and thus, attentional biases might be one mechanism by which impulsivity affects addictive behaviors. However, whether or not impulsivity is related to attentional biases across different conceptualizations of impulsivity and attentional biases has yet to be examined as an initial test of such causal models.

METHODS

The authors completed a meta-analysis of 13 published research studies examining the relationship between substance-related attentional bias and different conceptualizations of impulsivity.

RESULTS

There was a small and significant effect size between impulsivity and substance-related attentional bias (r=0.20), which was moderated by impulsivity measurement type (Qb=5.91, df=1, p<0.05): there was a stronger relationship between behavioral impulsivity and substance-related attentional bias (r=0.22) than trait impulsivity and substance-related attentional bias (r=0.10). Different components of behavioral impulsivity and trait impulsivity did not affect the relationship.

CONCLUSIONS

This study is the first systematic and empirical demonstration of the relationship between substance-related attentional bias and impulsivity and suggests viability of future examinations of casual models relating these constructs. Since trait and behavioral conceptualizations differentially relate to substance-related attentional bias, the current review further supports research suggesting how disaggregation of multidimensional constructs can lead to more robust relationships.

The behavioral- and neuro-economic process of temporal discounting: A candidate behavioral marker of addiction

Addiction science would benefit from the identification of a behavioral marker. A behavioral marker could reflect the projected clinical course of the disorder, function as a surrogate measure of clinical outcome, and/or may be related to biological components that underlie the disorder. In this paper we review relevant literature, made possible with the early and sustained support by NIDA, to determine whether temporal discounting, a neurobehavioral process derived from behavioral economics and further explored through neuroeconomics, may function as a behavioral marker. Our review suggests that temporal discounting 1) identifies individuals who are drug-dependent, 2) identifies those at risk of developing drug dependence, 3) acts as a gauge of addiction severity, 4) correlates with all stages of addiction development, 5) changes with effective treatment, and 6) may be related to the biological and genetic processes that underlie addiction. Thus, initial evidence supports temporal discounting as a candidate behavioral marker. Additional studies will be required in several areas for a more conclusive determination. Confirmation that temporal discounting functions as a behavioral marker for addiction could lead to 1) a screen for new treatments, 2) personalization of prevention and treatment interventions, and 3) the extension of temporal discounting as a behavioral marker for other etiologically similar disorders. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

A developmental perspective on neuroeconomic mechanisms of contingency management

This paper provides a developmental overview of relevant theory and research on delay discounting and neuroeconomics, and their implications for contingency management (CM) approaches to treatment. Recent advances in the neuroscience of decision making have the potential to inform treatment development for adolescent substance use in general, and CM treatments in particular. CM interventions may be informed by research on delay discounting, a type of decision making that reflects how individuals value immediate versus delayed rewards. Delay discounting reliably distinguishes substance abusers from nonabusers and is a significant predictor of individual differences in response to substance use treatments. Discounting may also be important in predicting response to CM, as CM attempts to directly influence this decision-making process, shifting the preference from the immediate rewards of use to delayed rewards for choosing not to use. Multiple neural processes underlie decision making, and those processes have implications for adolescent substance abuse. There are significant neurodevelopmental processes that differentiate adolescents from adults. These processes are implicated in delay discounting, suggesting that adolescence may reflect a period of plasticity in temporal decision making. Understanding the neural mechanisms of delay discounting has led to promising working memory interventions directly targeting the executive functions that underlie individual choices. These interventions may be particularly helpful in combination with CM interventions that offer immediate rewards for brief periods of abstinence, and may show particular benefit in adolescence due to the heightened neural plasticity of systems that underlie temporal discounting in adolescence.

Financial incentives for smoking cessation in pregnancy: protocol for a single arm intervention study

BACKGROUND

Smoking during pregnancy and in the postnatal period is a major cause of low birth weight and a range of adverse infant health outcomes. Stop smoking services can double quit rates, but only 17% of pregnant women smoking at the time they book for antenatal care use these services. In a recent Cochrane review on the effectiveness of smoking cessation interventions in pregnancy, financial incentives were found to be the single most effective intervention. We describe a single arm intervention study offering participation in a financial incentive scheme for smoking cessation to all pregnant smokers receiving antenatal care in one area in England. The aim of the study is to assess the potential effectiveness of using financial incentives to achieve smoking cessation in pregnant women who smoke, to inform the use of financial incentive schemes in routine clinical practice as well as the interpretation of existing trials and the design of future studies.

METHOD/DESIGN

500 consecutive pregnant smokers are offered participation in the scheme, which involves attending for up to 32 assessments until six months post-partum, to verify smoking cessation by self report and a negative exhaled carbon monoxide measurement. At each visit when cessation is verified, participants receive a shopping voucher starting at a value of £8 and increasing by £1 at each consecutive successful visit. Assessments decline in frequency, occurring most frequently during the first two weeks after quitting and the first two weeks after delivery. The maximum cumulative total that can be earned through the scheme is £752.

DISCUSSION

The results of this study will inform the use of financial incentive schemes in routine clinical practice as well as the interpretation of existing trials and the design of future studies. The main results are (a) an estimate of the proportion of pregnant smokers who enrol in the scheme; (b) estimates of the proportion of pregnant smokers who participate in the scheme and who achieve prolonged abstinence at: i. delivery and ii. six months postpartum; (c) predictors of i. participation in the scheme, and ii. smoking cessation; and (d) estimates of the adverse effects of using incentives to achieve quitting as indexed by: i. the delay in quitting smoking to enrol in an incentive scheme and, ii. false reporting of smoking status, either to gain entry into the scheme or to gain an incentive.

Delay discounting predicts adolescent substance abuse treatment outcome

The purpose of the current study was to identify predictors of delay discounting among adolescents receiving treatment for marijuana abuse or dependence, and to test delay discounting as a predictor of treatment outcome. Participants for this study were 165 adolescents (88% male) between the ages of 12 and 18 (mean age = 15.8 years; standard deviation = 1.3 years) who enrolled in a clinical trial comparing three behavioral treatments for adolescent marijuana abuse or dependence. Participants completed a delay discounting task at treatment onset for $100 and $1,000 of hypothetical money and marijuana. Overall, smaller magnitude rewards were discounted more than larger magnitude rewards. Delay discounting rates were concurrently related to demographic variables (socioeconomic status, race). Delay discounting of $1,000 of money predicted during treatment abstinence outcomes among adolescent marijuana abusers, over and above the effects of type of treatment received. Teens who show higher levels of discounting of the future may be an important subgroup to identify at treatment onset. Youth with a greater tendency to discount the future may require different intervention strategies that address their impulsivity (e.g., targeting executive function or inhibitory control) and/or different schedules of reinforcement to address their degree of preference for immediate rewards.

Temporal and probability discounting by cigarette smokers following acute smoking abstinence

INTRODUCTION

Given the lack of consensus regarding changes in temporal and probability discounting as a function of smoking abstinence in cigarette smokers, the present study comprehensively examined possible changes in these processes following a period of acute smoking abstinence consistent with elevated withdrawal symptoms and craving.

METHODS

Computerized temporal and probability discounting assessments were collected from cigarette smokers following normal smoking and 24-hr smoking abstinence, with the order of normal smoking and abstinence sessions counterbalanced across participants. Other conditions included commodity (money and cigarettes), sign (gains and losses), and magnitude ($50 and $1,000).

RESULTS

Twenty four-hour smoking abstinence resulted in a reduction in expired carbon monoxide to near-zero levels and increases in withdrawal and craving. Examination of discounting parameters as a function of smoking abstinence revealed a general pattern of increase in the temporal discounting of monetary gains and losses following abstinence but not in the temporal discounting of cigarettes nor probability discounting of money or cigarettes. Pearson correlations also revealed an expected pattern of significant relationships.

CONCLUSIONS

The present study is a comprehensive examination of temporal and probability discounting following smoking abstinence and reveals a generalized change in intertemporal decision making for monetary rewards.

Dependence and withdrawal-induced craving predict abstinence in an incentive-based model of smoking relapse

INTRODUCTION

Understanding factors that render some individuals more vulnerable to smoking relapse during the early stages of a quit attempt is critical to tailoring treatment efforts. Development of laboratory models of relapse can provide a framework for identifying underlying mechanisms that may contribute to vulnerability. Here, we explored predictors of abstinence in a novel incentive-based model of relapse.

METHODS

Fifty-six nontreatment seeking daily smokers completed several nicotine dependence measures prior to participating in a 1-week abstinence incentive test. During the abstinence procedure, participants earned monetary reinforcement for each biochemically verified day of abstinence according to a descending schedule of reinforcement.

RESULTS

Compliance with the procedure was excellent. All but 3 participants were able to initiate abstinence; nearly 70% lapsed as incentives were reduced. Scores on the Fagerström Test for Nicotine Dependence (FTND), number of cigarettes smoked per day, and self-reported craving on the first day of abstinence each independently predicted time to lapse. The single item of time to first cigarette in the morning on the FTND significantly predicted time to lapse, even when controlling for other significant predictors just listed. The Nicotine Dependence Syndrome Scale (NDSS) and Wisconsin Inventory of Smoking Dependence Motives did not predict lapse, but the NDSS did predict reinitiation of abstinence among those experiencing an initial lapse.

CONCLUSIONS

These findings partially replicate those of previous full-scale clinical trials and support the feasibility and validity of an incentive-based model of relapse. The time-limited and laboratory-based nature of this model has the potential to further investigations of underlying mechanisms contributing to relapse.

Effects of smoking abstinence on impulsive behavior among smokers high and low in ADHD-like symptoms

RATIONALE

Impulsivity, a multifaceted construct that includes inhibitory control and heightened preference for immediate reward, is central to models of drug use and abuse. Within a self-medication framework, abstinence from smoking may lead to an increase in impulsive behavior and the likelihood of relapse, particularly among persons with disorders (e.g., attention-deficit/hyperactivity disorder, ADHD) and personality traits (e.g., impulsivity) linked to impulsive behavior.

OBJECTIVES

This study aimed to examine the effects of smoking abstinence on multiple measures of impulsivity among a non-clinical sample of adult smokers selected for high and low levels of ADHD symptoms.

METHODS

In a within-subjects design, participants selected for high or low levels of self-reported ADHD symptoms (N = 56) completed sessions following overnight abstinence and when smoking as usual (order counterbalanced). Measures of impulsive behavior included response inhibition (i.e., stop signal task), interference control (i.e., attentional modification of prepulse inhibition (PPI) of startle), and impulsive choice (i.e., hypothetical delay discounting).

RESULTS

As hypothesized, abstinence decreased response inhibition and PPI. Although ADHD symptoms moderated abstinence effects on impulsive choice and response inhibition, the pattern was opposite to our predictions: the low-ADHD group responded more impulsively when abstinent, whereas the high-ADHD group was relatively unaffected by abstinence.

CONCLUSIONS

These findings highlight the importance of utilizing multiple laboratory measures to examine a multifactorial construct such as impulsive behavior and raise questions about how best to assess symptoms of ADHD and impulsivity among non-abstinent smokers.

The behavioral economics and neuroeconomics of reinforcer pathologies: implications for etiology and treatment of addiction

The current paper presents a novel approach to understanding and treating addiction. Drawing from work in behavioral economics and developments in the new field of neuroeconomics, we describe addiction as pathological patterns of responding resulting from the persistently high valuation of a reinforcer and/or an excessive preference for the immediate consumption of that reinforcer. We further suggest that, as indicated by the competing neurobehavioral decision systems theory, these patterns of pathological choice and consumption result from an imbalance between two distinct neurobehavioral systems. Specifically, pathological patterns of responding result from hyperactivity in the evolutionarily older impulsive system (which values immediate and low-cost reinforcers) and/or hypoactivity in the more recently evolved executive system (which is involved in the valuation of delayed reinforcers). This approach is then used to explain five phenomena that we believe any adequate theory of addiction must address.

The role of impulsivity in the aetiology of drug dependence: reward sensitivity versus automaticity

RATIONALE

Impulsivity has long been known as a risk factor for drug dependence, but the mechanisms underpinning this association are unclear. Impulsivity may confer hypersensitivity to drug reinforcement which establishes higher rates of instrumental drug-seeking and drug-taking behaviour, or may confer a propensity for automatic (non-intentional) control over drug-seeking/taking and thus intransigence to clinical intervention.

METHOD

The current study sought to distinguish these two accounts by measuring Barratt Impulsivity and craving to smoke in 100 smokers prior to their completion of an instrumental concurrent choice task for tobacco (to measure the rate of drug-seeking) and an ad libitum smoking test (to measure the rate of drug-taking-number of puffs consumed).

RESULTS

The results showed that impulsivity was not associated with higher rates of drug-seeking/taking, but individual differences in smoking uptake and craving were. Rather, nonplanning impulsivity moderated (decreased) the relationship between craving and drug-taking, but not drug-seeking.

CONCLUSIONS

These data suggest that whereas the uptake of drug use is mediated by hypervaluation of the drug as an instrumental goal, the orthogonal trait nonplanning impulsivity confers a propensity for automatic control over well-practiced drug-taking behaviour.

Remember the future: working memory training decreases delay discounting among stimulant addicts

BACKGROUND

Excessive discounting of future rewards has been observed in a variety of disorders and has been linked both to valuation of the past and to memory of past events.

METHODS

To explore the functionality of discounting and memory, we examined whether training of working memory would result in less discounting of future rewards. In this study, 27 adults in treatment for stimulant use were randomly assigned to receive either working memory training or control training according to a yoked experimental design. Measures of delay discounting and several other cognitive behaviors were assessed pre- and posttraining.

RESULTS

Rates of discounting of delayed rewards were significantly reduced among those who received memory training but were unchanged among those who received control training; other cognitive assessments were not affected by memory training. Discount rates were positively correlated with memory training performance measures.

CONCLUSIONS

To our knowledge, this is the first study demonstrating that neurocognitive training on working memory decreases delay discounting. These results offer further evidence of a functional relationship between delay discounting and working memory.

Clinical management of smoking cessation: patient factors affecting a reward-based approach

Although the majority of current smokers indicate they would like to quit, only about half of smokers make a quit attempt each year. Of those who attempt to quit, only about 5% are successful. Many effective products and programs are available to assist in smoking cessation; however those interested in quitting often do not make use of these resources. To increase use of cessation products in order to improve successful cessation rates, the Consumer Demand Roundtable has argued that smokers need to be viewed as consumers of cessation products rather than as patients needing treatment. With this consumer-based approach in mind, the current review examines how participant characteristics, perceptions, and behavior influence, and are influenced by, contingency management (CM) paradigms in various settings. Findings suggest that participant factors associated with success in these programs include demographic characteristics (eg, gender, marital status), self-efficacy, motivation to quit, and impulsivity. Overall, participants perceive incentives for successful cessation as motivating. However, such programs may involve greater withdrawal symptoms (eg, craving for cigarettes) initially, but these symptoms tend to decrease at a greater rate over time compared with nonincentive group participants. CM programs have also been shown to be successful across a number of settings (eg, communities, schools), including settings in which smokers are often considered difficult to treat (eg, substance abuse treatment centers). Overall, CM programs are perceived positively by participants and can increase rates of successful cessation. Furthermore, CM interventions have the flexibility to adapt to individual preferences and needs, leading to greater participation and likelihood of successful cessation. Thus, CM provides an important framework for addressing the need for consumer-focused smoking cessation interventions.