An fMRI investigation of the impact of withdrawal on regional brain activity during nicotine anticipation

A methodological checklist for fMRI drug cue reactivity studies: development and expert consensus

Cue reactivity is one of the most frequently used paradigms in functional magnetic resonance imaging (fMRI) studies of substance use disorders (SUDs). Although there have been promising results elucidating the neurocognitive mechanisms of SUDs and SUD treatments, the interpretability and reproducibility of these studies is limited by incomplete reporting of participants' characteristics, task design, craving assessment, scanning preparation and analysis decisions in fMRI drug cue reactivity (FDCR) experiments. This hampers clinical translation, not least because systematic review and meta-analysis of published work are difficult. This consensus paper and Delphi study aims to outline the important methodological aspects of FDCR research, present structured recommendations for more comprehensive methods reporting and review the FDCR literature to assess the reporting of items that are deemed important. Forty-five FDCR scientists from around the world participated in this study. First, an initial checklist of items deemed important in FDCR studies was developed by several members of the Enhanced NeuroImaging Genetics through Meta-Analyses (ENIGMA) Addiction working group on the basis of a systematic review. Using a modified Delphi consensus method, all experts were asked to comment on, revise or add items to the initial checklist, and then to rate the importance of each item in subsequent rounds. The reporting status of the items in the final checklist was investigated in 108 recently published FDCR studies identified through a systematic review. By the final round, 38 items reached the consensus threshold and were classified under seven major categories: 'Participants' Characteristics', 'General fMRI Information', 'General Task Information', 'Cue Information', 'Craving Assessment Inside Scanner', 'Craving Assessment Outside Scanner' and 'Pre- and Post-Scanning Considerations'. The review of the 108 FDCR papers revealed significant gaps in the reporting of the items considered important by the experts. For instance, whereas items in the 'General fMRI Information' category were reported in 90.5% of the reviewed papers, items in the 'Pre- and Post-Scanning Considerations' category were reported by only 44.7% of reviewed FDCR studies. Considering the notable and sometimes unexpected gaps in the reporting of items deemed to be important by experts in any FDCR study, the protocols could benefit from the adoption of reporting standards. This checklist, a living document to be updated as the field and its methods advance, can help improve experimental design, reporting and the widespread understanding of the FDCR protocols. This checklist can also provide a sample for developing consensus statements for protocols in other areas of task-based fMRI.

Better living through understanding the insula: Why subregions can make all the difference

Insula function is considered critical for many motivated behaviors, with proposed functions ranging from attention, behavioral control, emotional regulation, goal-directed and aversion-resistant responding. Further, the insula is implicated in many neuropsychiatric conditions including substance abuse. More recently, multiple insula subregions have been distinguished based on anatomy, connectivity, and functional contributions. Generally, posterior insula is thought to encode more somatosensory inputs, which integrate with limbic/emotional information in middle insula, that in turn integrate with cognitive processes in anterior insula. Together, these regions provide rapid interoceptive information about the current or predicted situation, facilitating autonomic recruitment and quick, flexible action. Here, we seek to create a robust foundation from which to understand potential subregion differences, and provide direction for future studies. We address subregion differences across humans and rodents, so that the latter's mechanistic interventions can best mesh with clinical relevance of human conditions. We first consider the insula's suggested roles in humans, then compare subregional studies, and finally describe rodent work. One primary goal is to encourage precision in describing insula subregions, since imprecision (e.g. including both posterior and anterior studies when describing insula work) does a disservice to a larger understanding of insula contributions. Additionally, we note that specific task details can greatly impact recruitment of various subregions, requiring care and nuance in design and interpretation of studies. Nonetheless, the central ethological importance of the insula makes continued research to uncover mechanistic, mood, and behavioral contributions of paramount importance and interest. This article is part of the special Issue on 'Neurocircuitry Modulating Drug and Alcohol Abuse'.

Revision of the Wisconsin Smoking Withdrawal Scale: Development of brief and long forms

The assessment of tobacco withdrawal is important for both research and clinical purposes. This study describes the psychometric development of a revised version of the 28-item Wisconsin Smoking Withdrawal Scale (WSWS; Welsch et al., Experimental and Clinical Psychopharmacology, 1999, 7, p. 354). Because the different contexts of use sometimes permit only brief assessment, this revision has produced both a brief and longer form using an updated pool of candidate items. For the revised Wisconsin Smoking Withdrawal Scale 2 (WSWS2), a candidate pool of 37 items was developed to measure nine putative withdrawal constructs. The stem and wording of items were revised as was the response scale. Data for psychometric analyses were derived from three smoking cessation randomized clinical trials conducted at the University of Wisconsin Center for Tobacco Research and Intervention. Dimensionality, internal consistency, and item characteristic analyses of the candidate items were conducted in a derivation sample to ascertain the factor structure and to identify items that could be used in the WSWS2 scales. Confirmatory factor analyses (CFAs) of reduced item sets and factor structure were conducted in two validation samples along with reliability and validity analyses. Derivation and validation sample analyses yielded a longer version of the WSWS2 (WSWS2-L) with 19 items and six subscales (Craving, Negative Affect, Hunger, Sleep, Restlessness, and Concentration) and a brief 6-item version (WSWS2-B). In validation sample analyses, both the WSWS2-L and the WSWS2-B demonstrated good reliability and validity as well as good fit in CFAs. The WSWS2-L and WSWS2-B possess improved construct coverage, fewer items, and other enhancements relative to the WSWS. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

BOLD activation during cue induced craving in adolescent inhalant users

Inhalants are legally available substances, most of them inexpensive, which are often abused by adolescents. Craving causes their continued use and repeated relapses. There is a need to understand the cue-induced craving and the associated neural mechanisms. In absence of any such prior study, the present study compared the hemodynamic changes in brain associated with craving effect in adolescent inhalant users and healthy controls using blood oxygen level dependent (BOLD) mechanism. This was an observational case control study with twelve adolescents, aged 12-18 years, with current use of inhalants as their primary drug, and twelve healthy, age and gender-matched adolescents, with no lifetime use of inhalants. Clinical assessments included Teen Addiction Severity Index and Visual Analogue Scale for craving. Participants abstained from all substances during 48 h prior to fMRI, confirmed by urinalysis. A validated visual cue block paradigm with neutral and craving cues was presented during the BOLD assessments in a 3 T MR system. The inhalant users exhibited BOLD activation in inferior frontal gyrus, inferior parietal lobule, superior occipital gyrus, cingulate gyrus, lentiform nucleus, thalamus, and culmen as compared to control group. The control group exhibited activation of insula as compared to cases. The results may be attributed to visuo-spatial attention, visual perception, working memory, and motivation associated with visual cue reactivity. This preliminary study provides important findings pertaining to activation patterns in response to cue-induced craving among adolescent inhalant users.

Non-pharmacological Considerations in Human Research of Nicotine and Tobacco Effects: A Review

Human research of nicotine and tobacco effects demonstrates that non-pharmacological factors may systematically affect responses to administered substances and inert placebos. Failure to measure or manipulate these factors may compromise study reliability and validity. This is especially relevant for double-blind placebo-controlled research of nicotine, tobacco, and related substances. In this article, we review laboratory-based human research of the impact of non-pharmacological factors on responses to tobacco and nicotine administration. Results suggest that varying beliefs about drug content and effects, perceptions about drug use opportunities, and intentions to cease drug use systematically alter subjective, behavioral, and physiological responses to nicotine, tobacco, and placebo administration. These non-pharmacological factors should be considered when designing and interpreting the findings of human research of nicotine and tobacco effects, particularly when a double-blind placebo-controlled design is used. The clinical implications of these findings are discussed, and we propose methodological strategies to enhance the reliability and validity of future research.

IMPLICATIONS

Growing research demonstrates that non-pharmacological factors systematically alter responses to acute nicotine, tobacco, and placebo administration. Indeed, varying beliefs about nicotine and/or tobacco administration and effects, differing perceptions about nicotine and/or tobacco use opportunities, and inconsistent motivation to quit smoking have been found to exert important influences on subjective, physiological, and behavioral responses. These variables are infrequently measured or manipulated in nicotine and tobacco research, which compromises the validity of study findings. Incorporating methodological strategies to better account for these non-pharmacological factors has the potential to improve the quality of addiction research and treatment.

Verbal suggestions of nicotine content modulate ventral tegmental neural activity during the presentation of a nicotine-free odor in cigarette smokers

Expectancies of nicotine content have been shown to impact smokers' subjective responses and smoking behaviors. However, little is known about the neural substrates modulated by verbally induced expectancies in smokers. In this study we used functional magnetic resonance imaging (fMRI) to investigate how verbally induced expectations, regarding the presence or absence of nicotine, modulated smokers' neural response to a nicotine-free odor. While laying in the scanner, all participants (N = 24) were given a nicotine-free odor, but whereas one group was correctly informed about the absence of nicotine (control group n = 12), the other group was led to believe that the presented odor contained nicotine (expectancy group n = 12). Smokers in the expectancy group had significantly increased blood-oxygen-level-dependent (BOLD) responses during the presentation of the nicotine-free odor in the left ventral tegmental area (VTA), and in the right insula, as compared to smokers in the control group (Regions of interest analysis with pFWE-corrected p ≤ 0.05). At a more liberal uncorrected statistical level (p-unc ≤ 0.001), increased bilateral reactivity in the dorsolateral prefrontal cortex (dlPFC) was also observed in the expectancy group as compared with the control group. Our findings suggest that nicotine-expectancies induced through verbal instructions can modulate nicotine relevant brain regions, without nicotine administration, and provide further neural support for the key role that cognitive expectancies play in the cause and treatment of nicotine dependence.

Comparing the reward value of cigarettes and food during tobacco abstinence and nonabstinence

BACKGROUND

Some addiction theories propose that nicotine dependence is characterized by an imbalance between motivation for cigarettes compared to non-drug rewards. This imbalance may become increasingly polarized during abstinence, which further potentiates smoking. The present study evaluated motivation for cigarettes and food during abstinence and nonabstinence in daily smokers. This study modified a previously validated cue-reactivity procedure to include food as a cue condition, thereby allowing the comparison of cigarettes to food and neutral cues. The Choice Behavior Under Cued Conditions (CBUCC) procedure, in which participants are presented with cues and spend money in order to gain immediate access to that cue, generates multiple variables to evaluate motivational factors and drug use behaviors including reward value, craving, seeking, choice time, and consumption.

METHODS

Fifty daily cigarette smokers underwent two CBUCC sessions under overnight abstinent and nonabstinent conditions.

RESULTS

As an index of reward value, participants spent more money to access cigarettes than food or water and more for food relative to water. Abstinence increased the reward value of cigarettes but did not significantly affect the reward value of food or water. Participants also demonstrated cue-specific craving for cigarettes and food, although overall cigarette craving was greater than food craving.

CONCLUSIONS

This study indicated that motivation was greater for cigarettes than food. Abstinence increased motivation for cigarettes but had little impact on motivation for food. This suggests that heavy smokers do not reallocate motivational resources towards cigarettes during abstinence; rather, motivational processes for food remain constant from nonabstinent to abstinent sessions.

A Neuronal Ensemble in the Rostral Agranular Insula Tracks Cocaine-Induced Devaluation of Natural Reward and Predicts Cocaine Seeking

In substance use disorders, negative affect associated with drug withdrawal can elicit strong drug craving and promote relapse. One brain region implicated in those processes is the rostral agranular insular cortex (RAIC), although precisely how this region encodes negative affect associated with drug seeking is unknown. Here, a preclinical model was used where RAIC activity was examined in male Sprague Dawley rats during intraoral infusions of a sweet (saccharin) paired with impending but delayed access to cocaine self-administration, and for comparative purposes, during the sweet predicting saline self-administration or injection of lithium chloride (LiCl), or during intraoral infusions of a bitter taste (quinine). Consistent with previous work, cocaine-paired saccharin, LiCl-paired saccharin, and quinine all elicited aversive taste reactivity. However, the aversive taste reactivity elicited by the cocaine-paired tastant was qualitatively different from that evoked by the other two agents. Furthermore, differences in taste reactivity were reflected in RAIC cell firing, where distinct shifts in neural signaling were observed specifically after cocaine but not LiCl conditioning. Notably, low motivation for cocaine (indicated by low loading and slower latencies to lever press) was correlated with this shift in RAIC signaling, but aversive (gaping) responses were not. Collectively, these findings indicate that cocaine-paired tastants elicit unique aspects of aversive behaviors that differ from traditional conditioned taste aversion (LiCl) or quinine and that the RAIC plays a role in modulating drug-seeking behaviors driven by drug-induced dysphoria (craving), but not negative affect per se.SIGNIFICANCE STATEMENT In substance use disorders, negative affect associated with drug cues can elicit craving and promote relapse; however, the underlying neurocircuitry of this phenomenon is unknown. Here, we investigated the role of the rostral agranular insula cortex (RAIC) in these processes using a preclinical model wherein intraoral delivery of a sweet is paired with delayed access to cocaine self-administration. The taste comes to elicit negative affect that predicts heightened drug seeking. Here, we found that a population of RAIC neurons became inhibited during presentation of the cocaine-paired tastant (when negative affect is high) and that this inhibitory neural profile predicted lower drug seeking. These findings suggest that the RAIC may function to oppose cue-induced cocaine craving and help reduce motivation for the drug.

Tick-tock goes the croc: a high-density EEG study of risk-reactivity and binge-drinking

Links between individual differences in risk processing and high-risk behaviors such as binge-drinking have long been the focus of active research. However, investigations in this area almost exclusively utilize decision-making focused paradigms. This emphasis makes it difficult to assess links between risk behaviors and raw risk reactivity independent of decision and feedback processes. A deeper understanding of this association has the potential to shed light on the role of risk reactivity in high-risk behavior susceptibility. To contribute toward this aim, this study utilizes a popular risk-taking game, the crocodile dentist, to assess links between individual differences in decision-free risk-reactivity and reported binge-drinking frequency levels. In this task, participants engage in a series of decision-free escalating risk responses. Risk-reactivity was assessed by measuring late positive potential responses toward risk-taking action initiation cues using high-density 256-Channel EEG. The results indicate that, after controlling for overall alcohol consumption frequency, higher rates of reported binge-drinking are associated with both increased general risk-taking responsivity and increased risk-reactivity escalation as a function of risk level. These findings highlight intriguing links between risk reactivity and binge-drinking frequency, making key contributions in the areas of risk-taking and affective science.

Neural Mechanisms of Circadian Regulation of Natural and Drug Reward

Circadian rhythms are endogenously generated near 24-hour variations of physiological and behavioral functions. In humans, disruptions to the circadian system are associated with negative health outcomes, including metabolic, immune, and psychiatric diseases, such as addiction. Animal models suggest bidirectional relationships between the circadian system and drugs of abuse, whereby desynchrony, misalignment, or disruption may promote vulnerability to drug use and the transition to addiction, while exposure to drugs of abuse may entrain, disrupt, or perturb the circadian timing system. Recent evidence suggests natural (i.e., food) and drug rewards may influence overlapping neural circuitry, and the circadian system may modulate the physiological and behavioral responses to these stimuli. Environmental disruptions, such as shifting schedules or shorter/longer days, influence food and drug intake, and certain mutations of circadian genes that control cellular rhythms are associated with altered behavioral reward. We highlight the more recent findings associating circadian rhythms to reward function, linking environmental and genetic evidence to natural and drug reward and related neural circuitry.

Smoking-induced affect modulation in nonwithdrawn smokers with posttraumatic stress disorder, depression, and in those with no psychiatric disorder

This research sought to determine whether smoking influences affect by means other than withdrawal reduction. Little previous evidence suggests such an effect. We surmised that such an effect would be especially apparent in posttraumatic stress disorder (PTSD) and major depressive disorder (MDD), 2 disorders that are frequently comorbid with smoking and that involve dysregulated affect. Participants were U.S. veterans who were regular smokers (N = 159): 52 with PTSD (58% with comorbid MDD), 51 with MDD, and 56 controls with no psychiatric disorder. During 3 positive and 3 negative mood induction trials (scheduled over 2 sessions), nonwithdrawn participants smoked either a nicotine-containing cigarette (NIC+), a nicotine-free cigarette (NIC-), or held a pen. Positive and negative affect were each measured before and after mood induction. Results showed a significant 2-way interaction of Smoking Condition × Time on negative affect during the negative mood induction (F(6, 576) = 2.41, p = .03) in those with PTSD and controls. In these groups, both NIC+ and NIC-, relative to pen, produced lower negative affect ratings after the negative mood induction. There was also a 2-way interaction of Smoking Condition × Time on positive affect response to the positive mood induction among those with PTSD and controls (F(6, 564) = 3.17, p = .005) and among MDD and controls (F(6, 564) = 2.27, p = .036). Among all smokers, NIC+ enhanced the magnitude and duration of positive affect more than did NIC-. Results revealed affect modulation outside the context of withdrawal relief; such effects may motivate smoking among those with psychiatric diagnoses, and among smokers in general. (PsycINFO Database Record

Long-term potentiation in autonomic ganglia: Potential role in cardiovascular disorders

Ganglionic long-term potentiation (gLTP) is an activity-dependent, enduring enhancement of ganglionic transmission. This phenomenon may be induced in autonomic ganglia of an organism under certain conditions where repetitive impulses surge from the central nervous system (CNS) to the periphery. Chronic stress, repetitive epileptic seizure or chronic use of CNS stimulants could induce gLTP, which would result in a long lasting heightening of sympathetic tone to the cardiovascular system causing hypertension and disturbed cardiac rhythm that may lead to sudden cardiac death. These conditions are briefly reviewed in this article.

Cigarette smoking leads to persistent and dose-dependent alterations of brain activity and connectivity in anterior insula and anterior cingulate

Although many smokers try to quit smoking, only about 20-25 percent will achieve abstinence despite 6 months or more of gold-standard treatment. This low success rate suggests long-term changes in the brain related to smoking, which remain poorly understood. We compared ex-smokers to both active smokers and non-smokers using functional magnetic resonance imaging (fMRI) to explore persistent modifications in brain activity and network organization. This prospective and consecutive study includes 18 non-smokers (29.5 ± 6.7 years of age, 11 women), 14 smokers (≥10 cigarettes a day >2 years of smoking, 29.3 ± 6.0 years of age, 10 women) and 14 ex-smokers (>1 year of quitting 30.5 ± 5.7 years of age, 10 women). Participants underwent a block-design fMRI study contrasting smoking cue with control (neutral cue) videos. Data analyses included task-related general linear model, seed-based functional connectivity, voxel-based morphometry (VBM) of gray matter and tract-based spatial statistics (TBSS) of white matter. Smoking cue videos versus control videos activated the right anterior insula in ex-smokers compared with smokers, an effect correlating with cumulative nicotine intake (pack-years). Moreover, ex-smokers had a persistent decrease in functional connectivity between right anterior insula and anterior cingulate cortex (ACC) compared with control participants, but similar to active smokers. Potentially confounding alterations in gray or white matter were excluded in VBM and TBSS analyses. In summary, ex-smokers with long-term nicotine abstinence have persistent and dose-dependent brain network changes notably in the right anterior insula and its connection to the ACC.

Smoking abstinence and neurocognition: implications for cessation and relapse

In this chapter, we review the last decade of research on the effects of smoking abstinence on various forms of neurocognition, including executive function (working memory, sustained attention, response inhibition), reward processing, and cue-reactivity. In our review we identify smoking abstinence-induced deficits in executive function mediated by effects on frontal circuitry, which in turn is known to be affected by modulation of cholinergic, dopaminergic, and other neurotransmitter systems. We also review evidence that smoking abstinence blunts reactivity to non-drug reinforcers-a finding that is consistent with results in the animal literature. Finally, our review of cue-reactivity indicates that smoking abstinence does not appear to amplify cue-provoked craving, although it may increase attentional bias to smoking-related cues. Inconsistencies across findings and potential contributing factors are discussed. In addition, we review the literature on the effects of nicotine and non-nicotine factors in neurocognition. Finally, we provide a multi-factor model and an agenda for future research on the effects of smoking abstinence on neurocognition. The model includes four distinct yet interacting factors, including: Negative Reinforcement, Drug-Reward Bias, Goal and Skill Interference, and Non-Cognitive Factors. Additional research is needed to further evaluate the scope and time-course of abstinence-induced changes in neurocognition, the mechanisms that underlie these changes and the specific role of these processes in drug reinforcement, lapse, and relapse.

Therapeutic Opportunities for Self-Control Repair in Addiction and Related Disorders: Change and the Limits of Change in Trans-Disease Processes

Contemporary neuro-economic approaches hypothesize that self-control failure results from drugs annexing normal learning mechanisms that produce pathological reward processing and distort decision-making as a result from the dysregulation of two valuation systems. An emphasis on processes shared across different diseases and disorders is at odds with the contemporary approach that assumes unique disease etiologies and treatments. Studying trans-disease processes can identify mechanisms that operate in multiple disease states and ascertain if factors that influence processes in one disease state may be applicable to all disease states. In this paper we review the dual model of self-control failure, the Competing Neurobehavioral Decision Systems approach, the relationship of delay discounting to the relative control of these two systems, and evidence that the executive system can be strengthened. Future research that could result in more potent interventions for executive system improvement and potential constraints on the repair of self-control failure are discussed.

Anhedonia as a component of the tobacco withdrawal syndrome

Animal research suggests that anhedonia is a tobacco withdrawal symptom, but this topic has not been addressed definitively in research with humans. This research sought to determine whether anhedonia is (a) an element of the tobacco withdrawal syndrome in humans and (b) an impediment to successful tobacco cessation. Data were from 1,175 smokers (58.3% women; 85.5% White) participating in a randomized double-blind, placebo-controlled trial of smoking cessation pharmacotherapies. Ecological momentary assessments for 5 days before and 10 days after the target quit day were used to assess anhedonia and other established withdrawal symptoms. Consistent with drug withdrawal, anhedonia showed an inverted-U pattern of change in response to tobacco cessation and was associated with the severity of other withdrawal symptoms and tobacco dependence. Postquit anhedonia was associated with decreased latency to relapse (hazard ratio = 1.09, 95% confidence interval [CI] [1.02, 1.17]) and with lower 8-week point-prevalence abstinence (odds ratio = .91, 95% CI [.86, .97])-relations that remained significant when other withdrawal symptoms were included as predictors. Finally, nicotine replacement therapy nearly fully suppressed the increase in abstinence-related anhedonia (β = -.66, p < .001), suggesting agonist suppression of withdrawal. Results suggest that anhedonia is a unique and motivationally significant element of the tobacco withdrawal syndrome in humans. These results have implications for defining and assessing tobacco use disorder and for understanding and treating tobacco addiction.

Dissociated effects of anticipating smoking versus monetary reward in the caudate as a function of smoking abstinence

BACKGROUND

Theories of addiction suggest that chronic smoking may be associated with both hypersensitivity to smoking and related cues and hyposensitivity to alternative reinforcers. However, neural responses to smoking and nonsmoking rewards are rarely evaluated within the same paradigm, leaving the extent to which both processes operate simultaneously uncertain. Behavioral evidence and theoretical models suggest that dysregulated reward processing may be more pronounced during deprivation from nicotine, but neuroimaging evidence on the effects of deprivation on reward processing is limited. The current study examined the impact of deprivation from smoking on neural processing of both smoking and monetary rewards.

METHODS

Two separate functional magnetic resonance imaging scans were performed in 38 daily smokers, one after smoking without restriction and one following 24 hours of abstinence. A rewarded guessing task was conducted during each scan to evaluate striatal blood oxygen level-dependent response during anticipation of both smoking and monetary rewards.

RESULTS

A significant reward type by abstinence interaction was observed in the bilateral caudate and medial prefrontal cortex during reward anticipation. The blood oxygen level-dependent response to anticipation of smoking reward was significantly higher and anticipation of monetary rewards was significantly lower during abstinence compared with nonabstinence. Attenuation of monetary reward-related activation during abstinence was significantly correlated with abstinence-induced increases in craving and withdrawal.

CONCLUSIONS

These results provide the first direct evidence of dissociated effects of smoking versus monetary rewards as a function of abstinence. The findings suggest an important neural pathway that may underlie the choice to smoke in lieu of alternative reinforcement during a quit attempt.

The effects of nicotine dose expectancy and motivationally relevant distracters on vigilance

The imminence of drug use (i.e., drug availability) has been found to be related to intensity of drug craving, but its effects on attentional bias to drug cues are unclear. This study investigated the effects of nicotine availability on attentional bias to smoking, affective, and neutral cues in a sample of adult smokers during a vigilance task. At the beginning of each of 4 laboratory sessions, overnight nicotine-deprived smokers (n = 51) were instructed that they would smoke a cigarette containing either nicotine (Told-NIC) or no nicotine (Told-DENIC) after completing the rapid visual information processing task with central emotional distracters (RVIP-CED). The RVIP-CED presented digits at a rapid pace, with participants instructed to respond with button presses to every third consecutive even or odd digit. Some digits were preceded by smoking, pleasant, unpleasant, or neutral distracter slides. During Told-NIC conditions, participants produced significantly longer reaction time (RT) latency than during Told-DENIC conditions. RT sensitivity (d'), a measure of the ability to discriminate true positives from false positives, was significantly lower during the Told-NIC than during the Told-DENIC conditions to targets following cigarette distracters. These results suggest that nicotine-deprived smokers expecting to imminently smoke a cigarette experience greater distraction, particularly to smoking-related stimuli, than when expecting to smoke a denicotinized cigarette.

The development and expression of physical nicotine dependence corresponds to structural and functional alterations in the anterior cingulate-precuneus pathway

INTRODUCTION

Perturbations in neural function provoked by a drug are thought to induce neural adaptations, which, in the absence of the drug, give rise to withdrawal symptoms. Previously published structural data from this study indicated that the progressive development of physical dependence is associated with increasing density of white matter tracts between the anterior cingulum bundle and the precuneus.

METHODS

Using functional magnetic resonance imaging, we compared 11 smokers after 11 h of abstinence from nicotine and after satiation, with 10 nonsmoking controls, using independent component analysis for brain network comparisons as well as a whole brain resting-state functional connectivity analysis using the anterior cingulate cortex as a seed.

RESULTS

Independent component analysis demonstrated increased functional connectivity in brain networks such as the default mode network associated with the withdrawal state in multiple brain regions. In seed-based analysis, smokers in the withdrawal state showed stronger functional connectivity than nonsmoking controls between the anterior cingulate cortex and the precuneus, caudate, putamen, and frontal cortex (P < 0.05). Among smokers, compared to the satiated state, nicotine withdrawal was associated with increased connectivity between the anterior cingulate cortex and the precuneus, insula, orbital frontal gyrus, superior frontal gyrus, posterior cingulate cortex, superior temporal, and inferior temporal lobe (P < 0.02). The intensity of withdrawal-induced craving correlated with the strength of connectivity between the anterior cingulate cortex and the precuneus, insula, caudate, putamen, middle cingulate gyrus, and precentral gyrus (r = 0.60-0.76; P < 0.05).

CONCLUSIONS

In concordance with our previous report that structural neural connectivity between the anterior cingulate area and the precuneus increased in proportion to the progression of physical dependence, resting-state functional connectivity in this pathway increases during nicotine withdrawal in correlation with the intensity of withdrawal-induced craving. These findings suggest that smoking triggers structural and functional neural adaptations in the brain that support withdrawal-induced craving.

Transcranial magnetic stimulation of the left dorsolateral prefrontal cortex decreases cue-induced nicotine craving and EEG delta power

BACKGROUND

TMS has high potential as smoking cessation treatment. However, the neural mechanisms underlying TMS induced reduction of tobacco craving remain unclear. Electroencephalographic (EEG) delta frequency has been associated with the activity of the dopaminergic brain reward system, which is crucial for nicotine induced effects, and decreases after nicotine admission in smokers.

OBJECTIVE

The aim of this study was to investigate EEG delta power changes induced by hf rTMS of the left dorsolateral prefrontal cortex (DLPFC) in nicotine deprived smokers and it's relation to cue-induced nicotine craving.

METHODS

Fourteen healthy smokers meeting ICD-10 criteria for tobacco addiction participated in this within-subject sham controlled study. Participants had to abstain from smoking 6 h before the experiment. Effects of high-frequency repetitive TMS (hf rTMS) (10 Hz) for verum (left DLPFC) and sham (vertex) stimulations on cue-induced nicotine craving and resting state EEG delta power were assessed before and three times within 40 min after rTMS.

RESULTS

Both craving (P = 0.046) and EEG delta power (P = 0.048) were significantly lower after verum stimulation compared to sham stimulation across the whole post stimulation time period assessed. However, changes of craving ratings and delta power did not correlate.

CONCLUSION

Hf rTMS applied to the left DLPFC reduces nicotine craving in short-term abstinent smokers. Changes in delta activity support the idea that stimulation induced effects are mediated by the dopaminergic brain reward system, which presumably plays a prominent, but probably not exclusive, role in this stimulation induced behavioral modulation, making this method a promising smoking cessation treatment candidate.

Functional data analysis for dynamical system identification of behavioral processes

Efficient new technology has made it straightforward for behavioral scientists to collect anywhere from several dozen to several thousand dense, repeated measurements on one or more time-varying variables. These intensive longitudinal data (ILD) are ideal for examining complex change over time but present new challenges that illustrate the need for more advanced analytic methods. For example, in ILD the temporal spacing of observations may be irregular, and individuals may be sampled at different times. Also, it is important to assess both how the outcome changes over time and the variation between participants' time-varying processes to make inferences about a particular intervention's effectiveness within the population of interest. The methods presented in this article integrate 2 innovative ILD analytic techniques: functional data analysis and dynamical systems modeling. An empirical application is presented using data from a smoking cessation clinical trial. Study participants provided 42 daily assessments of pre-quit and post-quit withdrawal symptoms. Regression splines were used to approximate smooth functions of craving and negative affect and to estimate the variables' derivatives for each participant. We then modeled the dynamics of nicotine craving using standard input-output dynamical systems models. These models provide a more detailed characterization of the post-quit craving process than do traditional longitudinal models, including information regarding the type, magnitude, and speed of the response to an input. The results, in conjunction with standard engineering control theory techniques, could potentially be used by tobacco researchers to develop a more effective smoking intervention.

Neural effects of positive and negative incentives during marijuana withdrawal

In spite of evidence suggesting two possible mechanisms related to drug-seeking behavior, namely reward-seeking and harm avoidance, much of the addiction literature has focused largely on positive incentivization mechanisms associated with addiction. In this study, we examined the contributing neural mechanisms of avoidance of an aversive state to drug-seeking behavior during marijuana withdrawal. To that end, marijuana users were scanned while performing the monetary incentive delay task in order to assess positive and negative incentive processes. The results showed a group x incentive interaction, such that marijuana users had greater response in areas that underlie reward processes during positive incentives while controls showed greater response in the same areas, but to negative incentives. Furthermore, a negative correlation between withdrawal symptoms and response in the amygdala during negative incentives was found in the marijuana users. These findings suggest that although marijuana users have greater reward sensitivity and less harm avoidance than controls, that attenuated amygdala response, an area that underlies fear and avoidance, was present in marijuana users with greater marijuana withdrawal symptoms. This is concordant with models of drug addiction that involve multiple sources of reinforcement in substance use disorders, and suggests the importance of strategies that focus on respective mechanisms.

Nicotine related brain activity: the influence of smoking history and blood nicotine levels, an exploratory study

OBJECTIVE

In this study, we sought to explore brain activity in nicotine-dependent men in response to acute intravenous nicotine using pharmacological magnetic resonance imaging (phMRI).

METHODS

phMRI was used to evaluate brain activity in response to 1.5 mg/70 kg intravenous nicotine or saline. The nicotine and saline were administered on different visits. The time courses of individual subjects' nicotine levels were used as regressors to assess neural activity relating to the infusions. The influence of smoking history and physiological measures on the response to nicotine were also investigated.

RESULTS

Greater lifetime exposure to cigarette smoking was significantly correlated with higher peak serum nicotine levels. PhMRI analysis of the differential response of nicotine compared to the saline condition showed distinctive activation patterns when analyzed with the (a) nicotine time course, (b) nicotine time course controlling for smoking history (pack years), and (c) pack years controlling for nicotine.

CONCLUSIONS

These results suggest that smoking exposure history influences serum nicotine levels and the brain's response to nicotine. Alterations in brain activity may be a result of vascular and neuro-adaptations involved in drug exposure and addiction.

Neural circuitry of impulsivity in a cigarette craving paradigm

Impulsivity has been shown to play a pivotal role in the onset, pattern of consumption, relapse and, most notably, craving of illicit and licit drugs such as cigarette smoking. The goal of this study was to examine the neurobiological influence of trait impulsivity during cue-induced cigarette craving. Thirty-one chronic smokers passively viewed appetitive smoking-related and neutral images while being scanned and reported their feelings of craving. They completed the Barratt Impulsiveness Scale, a measure of trait impulsivity. We conducted functional connectivity analyses using the psycho-physiological interaction method. During the processing of smoking stimuli, participants presented increased activations in the cingulate and prefrontal cortices. We observed a significant positive relationship between impulsivity scores and reported craving. A negative correlation was observed between the impulsivity score and activity in the posterior cingulate cortex (PCC). The insula, dorsal anterior cingulate cortex (dACC) as well as the dorsolateral prefrontal cortex (DLPFC) presented a negative connectivity with the PCC. Consistent with the view that the PCC is related to the ability to resist cigarette craving, our results suggest that high impulsive smokers have greater difficulty in controlling their cravings, and that this weakness may be mediated by lower PCC activity. Moreover, we argue that the less PCC activity, the greater the probability of a stronger emotional, physiological, and biased attentional response to smoking cues mediated by insula, dACC, and DLPFC activity. This is the first study on this topic, and so, results will need to be replicated in both licit and illicit drug abusers. Our findings also highlight a need for more emphasis on the PCC in drug addiction research, as it is one of the most consistently activated regions in functional magnetic resonance imaging studies examining the neural correlates of cue-induced alcohol, drug, and tobacco cravings.

Insula and orbitofrontal cortical morphology in substance dependence is modulated by sex

BACKGROUND AND PURPOSE

Frontolimbic circuits are involved in learning and decision-making processes thought to be affected in substance-dependent individuals. We investigated frontolimbic cortical morphometry in substance-dependent men and women and determined whether morphometric measurements correlated with decision-making performance.

MATERIALS AND METHODS

Twenty-eight abstinent SDI (17 men/11 women) were compared with 28 controls (13 men/15 women). Cortical thicknesses and volumes were computed by using FreeSurfer. After controlling for age and intracranial volume, group and sex effects were analyzed in 3 a priori regions of interest: the insula, orbitofrontal cortex, and anterior cingulate cortex by using analysis of covariance. A secondary whole-brain analysis was conducted to verify region-of-interest results and to explore potential differences in other brain regions.

RESULTS

Region-of-interest analyses revealed a main effect of group on the left insula cortex, which was thinner in SDI compared with controls (P = .02). There was a group by sex interaction on bilateral insula volume (left, P = .02; right, P = .001) and right insula cortical thickness (P = .007). Compared with same-sex controls, female SDI had smaller insulae, whereas male SDI had larger insulae. Neither ACC nor OFC significantly differed across group. Performance on a decision-making task was better in controls than SDI and correlated with OFC measurements in the controls.

CONCLUSIONS

SDI and controls differed in insula morphology, and those differences were modulated by sex. No group differences in OFC were observed, but OFC measurements correlated with negative-reinforcement learning in controls. These preliminary results are consistent with a hypothesis that frontolimbic pathways may be involved in behaviors related to substance dependence.

Are tobacco dependence and withdrawal related amongst heavy smokers? Relevance to conceptualizations of dependence

Measured tobacco dependence is typically only modestly related to tobacco withdrawal severity among regular smokers making a quit attempt. The weak association between dependence and withdrawal is notable because it conflicts with core theories of dependence and because both measures predict cessation outcomes, suggesting they both index a common dependence construct. This study used data from a smoking cessation comparative effectiveness trial (N = 1504) to characterize relations of tobacco dependence with craving and negative affect withdrawal symptoms using multiple dependence measures and analytic methods to detect both additive and interactive effects and to determine whether withdrawal meaningfully mediates the influence of dependence on smoking cessation. We conclude: (a) Although univariate analyses suggest dependence and withdrawal measures are only modestly interrelated, more powerful analytic techniques show they are, in fact, meaningfully related and their shared variance is associated with cessation likelihood; (b) there are clear differences between craving and negative affective withdrawal symptoms, with the former more related to smoking heaviness and the latter related to trait measures of negative affect; moreover, craving more strongly mediates dependence effects on cessation; and (c) both craving and negative affect withdrawal symptoms are strongly related to a pattern of regular smoking that is sensitive to the passage of time and powerfully affected by smoking cues. These findings support models that accord an important role for associative processes and withdrawal symptoms, especially craving, in drug dependence. The findings also support the use of withdrawal variables as criteria for the evaluation of dependence measures.

Why two smoking cessation agents work better than one: role of craving suppression

OBJECTIVE

This research examined why smokers receiving combination medication for smoking cessation are more likely to quit smoking than are those who receive either single agent (monotherapy) or placebo.

METHOD

Data were collected from 1,504 current smokers (58.2% women, 83.9% White; mean age = 44.67 years, SD = 11.08) participating in a cessation clinical trial who were randomized to 1 of 6 cessation pharmacotherapy conditions (placebo, nicotine patch, nicotine lozenge, bupropion, nicotine patch + nicotine lozenge, and bupropion + nicotine lozenge). Participants completed ecological momentary assessments 4 times a day, concerning 5 hypothesized mediators (negative affect, positive affect, craving, smoking expectations, and withdrawal) of pharmacotherapy effects. Medications were provided for 8-12 weeks post-quit along with 6 individual counseling sessions. Mediational paths were estimated via a novel Bayesian approach with estimation of multiple mediator models.

RESULTS

Biochemically confirmed 8-week abstinence was the outcome variable, with the monotherapy and combination pharmacotherapy composites producing 45% (n = 689) and 54% (n = 478) abstinence rates, respectively. The univariate models suggested that the combination treatments produced higher abstinence rates than the monotherapies because of greater suppression of withdrawal, craving, and smoking expectations. However, multiple mediator models showed that the suppression of craving on the quit day produced the strongest mediational effects and could account for the mediational effects of other tested variables.

CONCLUSION

Suppression of craving on the quit day significantly mediates the clinical effects of monotherapies and combination smoking pharmacotherapies, and the higher abstinence rates for combination therapy versus monotherapies appear primarily due to greater craving suppression.

Neural substrates of smoking cue reactivity: a meta-analysis of fMRI studies

Reactivity to smoking-related cues may be an important factor that precipitates relapse in smokers who are trying to quit. The neurobiology of smoking cue reactivity has been investigated in several fMRI studies. We combined the results of these studies using activation likelihood estimation, a meta-analytic technique for fMRI data. Results of the meta-analysis indicated that smoking cues reliably evoke larger fMRI responses than neutral cues in the extended visual system, precuneus, posterior cingulate gyrus, anterior cingulate gyrus, dorsal and medial prefrontal cortex, insula, and dorsal striatum. Subtraction meta-analyses revealed that parts of the extended visual system and dorsal prefrontal cortex are more reliably responsive to smoking cues in deprived smokers than in non-deprived smokers, and that short-duration cues presented in event-related designs produce larger responses in the extended visual system than long-duration cues presented in blocked designs. The areas that were found to be responsive to smoking cues agree with theories of the neurobiology of cue reactivity, with two exceptions. First, there was a reliable cue reactivity effect in the precuneus, which is not typically considered a brain region important to addiction. Second, we found no significant effect in the nucleus accumbens, an area that plays a critical role in addiction, but this effect may have been due to technical difficulties associated with measuring fMRI data in that region. The results of this meta-analysis suggest that the extended visual system should receive more attention in future studies of smoking cue reactivity.

Quitting-unmotivated and quitting-motivated cigarette smokers exhibit different patterns of cue-elicited brain activation when anticipating an opportunity to smoke

The authors examined the effects of smoking expectancy on cue-reactivity among those motivated and those unmotivated to quit smoking using functional MRI. Cue-elicited activation was observed in the rostral prefrontal cortex (PFC) in smokers who expected to smoke within seconds, but not in those who expected to have to wait hours before having the chance to smoke, regardless of quitting motivation. For quitting-unmotivated smokers expecting to smoke, rostral PFC activation was strongly positively correlated with the activation of several areas previously linked to cue-reactivity, including the medial orbitofrontal cortex (OFC) and rostral anterior cingulate cortex (ACC). In contrast, there was a nonsignificant negative relationship between activation of the rostral PFC and activation of the medial OFC/rostral ACC in quitting-motivated smokers expecting to smoke. Results extend previous work examining the effects of smoking expectancy and highlight the utility of examining interregional covariation during cue exposure. Findings also suggest that investigators may need to pay close attention to the motivational contexts associated with their experiments when studying cue-reactivity, as these contexts can modulate not only responses to drug cues, but perhaps also the functional implications of observed activity.

Tobacco withdrawal components and their relations with cessation success

RATIONALE

Tobacco withdrawal is a key factor in smoking relapse, but important questions about the withdrawal phenomenon remain.

OBJECTIVES

This research was intended to provide information about two core components of withdrawal (negative affect and craving): (1) how various withdrawal symptom profile dimensions (e.g., mean level, volatility, extreme values) differ between negative affect and craving; and (2) how these dimensions relate to cessation outcome.

METHODS

Adult smokers (N = 1,504) in a double-blind randomized placebo-controlled smoking cessation trial provided real-time withdrawal symptom data four times per day for 4 weeks (2 weeks pre-quit and 2 weeks post-quit) via palmtop computers. Cessation outcome was biochemically confirmed 8-week point-prevalence abstinence.

RESULTS

Examination of craving and negative affect dimensions following a cessation attempt revealed that craving symptoms differed from negative affect symptoms, with higher means, greater variability, and a greater incidence of extreme peaks. Regression analyses revealed that abstinence was associated with lower mean levels of both craving and negative affect and fewer incidences of extreme craving peaks. In a multivariate model, the increase in mean craving and negative affect scores each uniquely predicted relapse.

CONCLUSIONS

Real-time reports revealed different patterns of abstinence-related negative affect and craving and that dimensions of both predict cessation outcome, suggesting that negative affect and craving dimensions each has motivational significance. This underscores the complexity of withdrawal as a determinant of relapse and the need to measure its distinct components and dimensions.

Deconstructing craving: dissociable cortical control of cue reactivity in nicotine addiction

BACKGROUND

Cue reactivity, the ability of cues associated with addictive substances to induce seeking and withdrawal, is a major contributor to addiction. Although human imaging studies show that cigarette-associated cues simultaneously activate the insula and the orbitofrontal cortex and evoke craving, how these activities functionally contribute to distinct elements of cue reactivity remains unclear. Moreover, it remains unclear whether the simultaneous activation of these cortical regions reflects coordinated functional connectivity or parallel processing.

METHODS

We selectively lesioned the insula or orbitofrontal cortex with the excitotoxin ibotenic acid in mice, and their approach to nicotine-associated cues (n = 6-13/group) and avoidance of withdrawal-associated cues (n = 5-12/group) were separately examined in place conditioning paradigms. We additionally tested the role of these two cortical structures in approach to food-associated cues (n = 6-7/group) and avoidance of lithium chloride-associated cues (n = 6-7/group).

RESULTS

Our data show a double dissociation in which excitotoxic lesions of the insula and orbitofrontal cortex selectively disrupted nicotine-induced cue approach and withdrawal-induced cue avoidance, respectively. These effects were not entirely generalized to approach to food-associated cues or avoidance of lithium chloride-associated cues.

CONCLUSIONS

Our data provide functional evidence that cue reactivity seen in addiction includes unique neuroanatomically dissociable elements and suggest that the simultaneous activation of these two cortical regions in response to smoking-related cues does not necessarily indicate functional connectivity.

Cognitive conflict following appetitive versus negative cues and smoking cessation failure

RATIONALE

Attentional biases and executive control deficits may play a role in smoking cessation failure.

OBJECTIVES

The object of this study was to determine whether smokers' pre-quit reaction times on a computerized modified Simon task (which assesses attentional biases and executive control deficits) predict abstinence following a quit attempt.

METHODS

Participants (N = 365) in a larger smoking cessation clinical trial completed the modified Simon task twice (while 10-h nicotine-deprived vs. not deprived). In the task, two photographs (i.e., two digital slides) were displayed—one always neutral, the other positive, negative, smoking-relevant, or neutral. A probe (<<< or >>>) then appeared to the left or right of center, and participants indicated the arrow's direction (left or right) which was either congruent or incongruent with the arrow's location on the screen. The incongruency effect, a measure of executive control, was calculated by subtracting the reaction time to congruent probes from the reaction time to incongruent probes.

RESULTS

Greater impairment in executive control (i.e., greater probe incongruency effects) after viewing positive and smoking slides relative to negative slides predicted an inability to establish initial cessation and to maintain abstinence up to 8 weeks post-quit.

CONCLUSIONS

These effects may be because smokers who avoid/escape from processing negative affect are more likely to fail in a cessation attempt. Differences in relatively automatic responses to affective cues distinguish smokers who are successful and unsuccessful in their smoking cessation attempts, but effects were modest in size.

New methods for tobacco dependence treatment research

INTRODUCTION

Despite advances in tobacco dependence treatment in the past two decades, progress has been inconsistent and slow. This paper reviews pervasive methodological issues that may contribute to the lack of timely progress in tobacco treatment science including the lack of a dynamic model or framework of the cessation process, inefficient study designs, and the use of distal outcome measures that poorly index treatment effects. The authors then present a phase-based cessation framework that partitions the cessation process into four discrete phases based on current theories of cessation and empirical data. These phases include: (1) Motivation, (2) Precessation, (3) Cessation, and (4) Maintenance.

DISCUSSION

Within this framework, it is possible to identify phase-specific challenges that a smoker would encounter while quitting smoking, intervention components that would address these phase-specific challenges, mechanisms via which such interventions would exert their effects, and optimal outcome measures linked to these phase-specific interventions. Investigation of phase-based interventions can be accelerated by using efficient study designs that would permit more timely development of an optimal smoking cessation treatment package.

Smoker characteristics and smoking-cessation milestones

BACKGROUND

Contextual variables often predict long-term abstinence, but little is known about how these variables exert their effects. These variables could influence abstinence by affecting the ability to quit at all, or by altering risk of lapsing, or progressing from a lapse to relapse.

PURPOSE

To examine the effect of common predictors of smoking-cessation failure on smoking-cessation processes.

METHODS

The current study (N=1504, 58% female, 84% Caucasian; recruited from January 2005 to June 2007; data analyzed in 2009) uses the approach advocated by Shiffman et al. (2006), which measures cessation outcomes on three different cessation milestones (achieving initial abstinence, lapse risk, and the lapse-relapse transition) to examine relationships of smoker characteristics (dependence, contextual and demographic factors) with smoking-cessation process.

RESULTS

High nicotine dependence strongly predicted all milestones: not achieving initial abstinence, and a higher risk of both lapse and transitioning from lapse to complete relapse. Numerous contextual and demographic variables were associated with higher initial cessation rates and/or decreased lapse risk at 6 months post-quit (e.g., ethnicity, gender, marital status, education, smoking in the workplace, number of smokers in the social network, and number of supportive others). However, aside from nicotine dependence, only gender significantly predicted the risk of transition from lapse to relapse.

CONCLUSIONS

These findings demonstrate that (1) higher nicotine dependence predicted worse outcomes across every cessation milestone; (2) demographic and contextual variables are generally associated with initial abstinence rates and lapse risk and not the lapse-relapse transition. These results identify groups who are at risk for failure at specific stages of the smoking-cessation process, and this may have implications for treatment.

Anxiety diagnoses in smokers seeking cessation treatment: relations with tobacco dependence, withdrawal, outcome and response to treatment

AIMS

To understand the relations among anxiety disorders and tobacco dependence, withdrawal symptoms, response to smoking cessation pharmacotherapy and ability to quit smoking.

DESIGN

Randomized placebo-controlled clinical trial. Participants received six 10-minute individual counseling sessions and either: placebo, bupropion SR, nicotine patch, nicotine lozenge, bupropion SR + nicotine lozenge or nicotine patch + nicotine lozenge.

SETTING

Two urban research sites.

PARTICIPANTS

Data were collected from 1504 daily smokers (>9 cigarettes per day) who were motivated to quit smoking and did not report current diagnoses of schizophrenia or psychosis or bupropion use.

MEASUREMENTS

Participants completed baseline assessments, the Composite International Diagnostic Interview and ecological momentary assessments for 2 weeks.

FINDINGS

A structured clinical interview identified participants who ever met criteria for a panic attack (n = 455), social anxiety (n = 199) or generalized anxiety disorder (n = 99), and those who qualified for no anxiety diagnosis (n = 891). Smokers with anxiety disorders reported higher levels of nicotine dependence and pre-quit withdrawal symptoms. Those ever meeting criteria for panic attacks or social anxiety disorder showed greater quit-day negative affect. Smokers ever meeting criteria for anxiety disorders were less likely to be abstinent at 8 weeks and 6 months post-quit and showed no benefit from single-agent or combination-agent pharmacotherapies.

CONCLUSIONS

Anxiety diagnoses were common among treatment-seeking smokers and were related to increased motivation to smoke, elevated withdrawal, lack of response to pharmacotherapy and impaired ability to quit smoking. These findings could guide treatment assignment algorithms and treatment development for smokers with anxiety diagnoses.

Effect of bupropion treatment on brain activation induced by cigarette-related cues in smokers

CONTEXT

Nicotine-dependent smokers exhibit craving and brain activation in the prefrontal and limbic regions when presented with cigarette-related cues. Bupropion hydrochloride treatment reduces cue-induced craving in cigarette smokers; however, the mechanism by which bupropion exerts this effect has not yet been described.

OBJECTIVE

To assess changes in regional brain activation in response to cigarette-related cues from before to after treatment with bupropion (vs placebo).

DESIGN

Randomized, double-blind, before-after controlled trial.

SETTING

Academic brain imaging center.

PARTICIPANTS

Thirty nicotine-dependent smokers (paid volunteers).

INTERVENTIONS

Participants were randomly assigned to receive 8 weeks of treatment with either bupropion or a matching placebo pill (double-blind).

MAIN OUTCOME MEASURES

Subjective cigarette craving ratings and regional brain activations (blood oxygen level-dependent response) in response to viewing cue videos.

RESULTS

Bupropion-treated participants reported less craving and exhibited reduced activation in the left ventral striatum, right medial orbitofrontal cortex, and bilateral anterior cingulate cortex from before to after treatment when actively resisting craving compared with placebo-treated participants. When resisting craving, reduction in self-reported craving correlated with reduced regional brain activation in the bilateral medial orbitofrontal and left anterior cingulate cortices in all participants.

CONCLUSIONS

Treatment with bupropion is associated with improved ability to resist cue-induced craving and a reduction in cue-induced activation of limbic and prefrontal brain regions, while a reduction in craving, regardless of treatment type, is associated with reduced activation in prefrontal brain regions.

Explicating an evidence-based, theoretically informed, mobile technology-based system to improve outcomes for people in recovery for alcohol dependence

Post-treatment relapse to uncontrolled alcohol use is common. Currently available communication technology can use existing models for relapse prevention to cost-effectively improve long-term relapse prevention. This paper describes: (1) research-based elements of alcohol consumption-related relapse prevention and how they can be encompassed in self-determination theory (SDT) and Marlatt's cognitive behavioral relapse prevention model, (2) how technology could help address the needs of people seeking recovery, (3) a technology-based prototype, organized around sexual transmitted disease and Marlatt's model, and (4) how we are testing a system based on the ideas in this article and related ethical and operational considerations.

Diffusion tensor imaging and decision making in cocaine dependence

BACKGROUND

Chronic stimulant abuse is associated with both impairment in decision making and structural abnormalities in brain gray and white matter. Recent data suggest these structural abnormalities may be related to functional impairment in important behavioral processes.

METHODOLOGY/PRINCIPAL FINDINGS

In 15 cocaine-dependent and 18 control subjects, we examined relationships between decision-making performance on the Iowa Gambling Task (IGT) and white matter integrity as measured by diffusion tensor imaging (DTI). Whole brain voxelwise analyses showed that, relative to controls, the cocaine group had lower fractional anisotropy (FA) and higher mean of the second and third eigenvalues (lambda perpendicular) in frontal and parietal white matter regions and the corpus callosum. Cocaine subjects showed worse performance on the IGT, notably over the last 40 trials. Importantly, FA and lambda perpendicular values in these regions showed a significant relationship with IGT performance on the last 40 trials.

CONCLUSIONS

Compromised white matter integrity in cocaine dependence may be related to functional impairments in decision making.

Insula and drug cravings

This paper reviews the role of the insula in drug craving. Evidence is presented that drug craving may be a particular instance of the anterior insula's broader role in interoception and subjective feeling states similar, for example, to thirst and hunger. An important role for the insula in craving is supported by evidence of insular activity changing with satiety and with the top-down cognitive modulation of cravings. Cognitive processes involving the insula's role in awareness of one's own behaviour may also contribute to craving insofar as the avoidance of craving might require subjective awareness of the endogenous and exogenous cues that initiate it. Finally, some consideration is given to sex differences and developmental processes in craving.

Current Status and Future Prospects of Clinical Psychology: Toward a Scientifically Principled Approach to Mental and Behavioral Health Care

The escalating costs of health care and other recent trends have made health care decisions of great societal import, with decision-making responsibility often being transferred from practitioners to health economists, health plans, and insurers. Health care decision making increasingly is guided by evidence that a treatment is efficacious, effective-disseminable, cost-effective, and scientifically plausible. Under these conditions of heightened cost concerns and institutional-economic decision making, psychologists are losing the opportunity to play a leadership role in mental and behavioral health care: Other types of practitioners are providing an increasing proportion of delivered treatment, and the use of psychiatric medication has increased dramatically relative to the provision of psychological interventions. Research has shown that numerous psychological interventions are efficacious, effective, and cost-effective. However, these interventions are used infrequently with patients who would benefit from them, in part because clinical psychologists have not made a convincing case for the use of these interventions (e.g., by supplying the data that decision makers need to support implementation of such interventions) and because clinical psychologists do not themselves use these interventions even when given the opportunity to do so. Clinical psychologists' failure to achieve a more significant impact on clinical and public health may be traced to their deep ambivalence about the role of science and their lack of adequate science training, which leads them to value personal clinical experience over research evidence, use assessment practices that have dubious psychometric support, and not use the interventions for which there is the strongest evidence of efficacy. Clinical psychology resembles medicine at a point in its history when practitioners were operating in a largely prescientific manner. Prior to the scientific reform of medicine in the early 1900s, physicians typically shared the attitudes of many of today's clinical psychologists, such as valuing personal experience over scientific research. Medicine was reformed, in large part, by a principled effort by the American Medical Association to increase the science base of medical school education. Substantial evidence shows that many clinical psychology doctoral training programs, especially PsyD and for-profit programs, do not uphold high standards for graduate admission, have high student-faculty ratios, deemphasize science in their training, and produce students who fail to apply or generate scientific knowledge. A promising strategy for improving the quality and clinical and public health impact of clinical psychology is through a new accreditation system that demands high-quality science training as a central feature of doctoral training in clinical psychology. Just as strengthening training standards in medicine markedly enhanced the quality of health care, improved training standards in clinical psychology will enhance health and mental health care. Such a system will (a) allow the public and employers to identify scientifically trained psychologists; (b) stigmatize ascientific training programs and practitioners; (c) produce aspirational effects, thereby enhancing training quality generally; and (d) help accredited programs improve their training in the application and generation of science. These effects should enhance the generation, application, and dissemination of experimentally supported interventions, thereby improving clinical and public health. Experimentally based treatments not only are highly effective but also are cost-effective relative to other interventions; therefore, they could help control spiraling health care costs. The new Psychological Clinical Science Accreditation System (PCSAS) is intended to accredit clinical psychology training programs that offer high-quality science-centered education and training, producing graduates who are successful in generating and applying scientific knowledge. Psychologists, universities, and other stakeholders should vigorously support this new accreditation system as the surest route to a scientifically principled clinical psychology that can powerfully benefit clinical and public health.