Imagery-induced tobacco craving: duration and lack of assessment reactivity bias

Effect of Implementation Facilitation to Promote Adoption of Medications for Addiction Treatment in US HIV Clinics: A Randomized Clinical Trial

Importance

Medications for addiction treatment (MAT) are inconsistently offered in HIV clinics.

Objective

To evaluate the impact of implementation facilitation (hereafter referred to as "facilitation"), a multicomponent implementation strategy, on increasing provision of MAT for opioid use disorder (MOUD), alcohol use disorder (MAUD), and tobacco use disorder (MTUD).

Design, Setting, and Participants

Conducted from July 26, 2016, through July 25, 2020, the Working with HIV Clinics to adopt Addiction Treatment using Implementation Facilitation (WHAT-IF?) study used an unblinded, stepped wedge design to sequentially assign each of 4 HIV clinics in the northeastern US to cross over from control (ie, baseline practices) to facilitation (ie, intervention) and then evaluation and maintenance periods every 6 months. Participants were adult patients with opioid, alcohol, or tobacco use disorder. Data analysis was performed from August 2020 to September 2022.

Interventions

Multicomponent facilitation.

Main Outcomes and Measures

Outcomes, assessed using electronic health record data, were provision of MAT among patients with opioid, alcohol, or tobacco use disorder during the evaluation (primary outcome) and maintenance periods compared with the control period.

Results

Among 3647 patients, the mean (SD) age was 49 (12) years, 1814 (50%) were Black, 781 (22%) were Hispanic, and 1407 (39%) were female; 121 (3%) had opioid use disorder, 126 (3%) had alcohol use disorder, and 420 (12%) had tobacco use disorder. Compared with the control period, there was no increase in provision of MOUD with facilitation during the evaluation period (243 patients [27%; 95% CI, 22%-32%] vs 135 patients [28%; 95% CI, 22%-35%]; P = .59) or maintenance period (198 patients [29%; 95% CI, 22%-36%]; P = .48). The change in provision of MAUD from the control period to the evaluation period was not statistically significant (251 patients [8%; 95% CI, 5%-12%] vs 112 patients [13%; 95% CI, 8%-21%]; P = .11); however, the difference increased and became significant during the maintenance period (180 patients [17%; 95% CI, 12%-24%]; P = .009). There were significant increases in provision of MTUD with facilitation during both the evaluation (810 patients [33%; 95% CI, 30%-36%] vs 471 patients [40%; 95% CI, 36%-45%]; P = .005) and maintenance (643 patients [38%; 95% CI, 34%-41%]; P = .047) periods.

Conclusions and Relevance

In this randomized clinical trial, facilitation led to increased provision of MTUD, delayed improvements in MAUD, and no improvements in MOUD in HIV clinics. Enhanced strategies, potentially including clinic and patient incentives, especially for MOUD, may be needed to further increase provision of MAT in HIV clinics.

Trial Registration

ClinicalTrials.gov Identifier: NCT02907944.

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.

Psychometric properties of the transaddiction craving triggers questionnaire in alcohol use disorder

OBJECTIVES

We aimed to develop the transaddiction craving triggers questionnaire (TCTQ), which assesses the propensity of specific situations and contexts to trigger craving and to test its psychometric properties in alcohol use disorder (AUD).

METHODS

This study included a sample of 111 AUD outpatients. We performed exploratory factor analysis (EFA) and calculated item-dimension correlations. Internal consistency was measured with Cronbach's alpha coefficient. Construct validity was assessed through Spearman correlations with craving, emotional symptoms, impulsivity, mindfulness, and drinking characteristics.

RESULTS

The EFA suggested a 3-factor solution: unpleasant affect, pleasant affect, and cues and related thoughts. Cronbach's coefficient alpha ranged from .80 to .95 for the three factors and the total score. Weak positive correlations were identified between the TCTQ and drinking outcomes, and moderate correlation were found between the TCTQ and craving strength, impulsivity, anxiety, depression, and impact of alcohol on quality of life.

CONCLUSIONS

The 3-factor structure is congruent with the well-established propensity of emotions and cues to trigger craving. Construct validity is supported by close relations between the TCTQ and psychological well-being rather than between the TCTQ and drinking behaviors. Longitudinal validation is warranted to assess sensitivity to change of the TCTQ and to explore its psychometric properties in other addictive disorders.

Nicotine effects on associative learning in human non-smokers

Tobacco smoking is the most common preventable cause of death in the US. Nicotine is considered the primary constituent responsible for tobacco addiction. Its paradoxically high abuse potential may reflect behavioral control by drug-associated stimuli, which appears to play a larger role for tobacco dependence than for other abused drugs. We tested a potential explanation, hypothesizing that nicotine enhances associative learning, the mechanism underlying the conditioning of drug-associated stimuli. Thirty-two non-smokers were exposed to transdermal nicotine (7 mg/24 h) and placebo in a double-blind cross-over study and tested with behavioral paradigms designed to isolate incidental stimulus-stimulus or stimulus-response learning. The stop signal task required speeded gender judgments of face stimuli. A tone signaled when to withhold the response. Unbeknownst to participants, some faces were always paired with stop trials. Nicotine enhanced the facilitation of stop-responses to these stimuli, and the slowing of go-responses when previously stop-associated stimuli were paired with go trials, indicating stronger associations between paired stimuli and the stop signal/stop response. Another task required feedback-based learning of associations between pairs of shape stimuli. Five pairs were made from either ten different stimuli, or from different combinations of two identical sets of five stimuli with correct associations depending on contextual information. Nicotine increased incorrect choices of stimuli that were associated in a different context, indicating stronger stimulus-stimulus associations at the expense of flexible context-adaptive behavior. The results indicate that nicotine can enhance incidental associative learning, a mechanism that may promote the formation of smoking-associated stimuli and cue-controlled drug-taking.

Introspective responses to cues and motivation to reduce cigarette smoking influence state and behavioral responses to cue exposure

In the current study, we aimed to extend smoking cue-reactivity research by evaluating delay discounting as an outcome of cigarette cue exposure. We also separated introspection in response to cues (e.g., self-reporting craving and affect) from cue exposure alone, to determine if introspection changes behavioral responses to cigarette cues. Finally, we included measures of quit motivation and resistance to smoking to assess motivational influences on cue exposure. Smokers were invited to participate in an online cue-reactivity study. Participants were randomly assigned to view smoking images or neutral images, and were randomized to respond to cues with either craving and affect questions (e.g., introspection) or filler questions. Following cue exposure, participants completed a delay discounting task and then reported state affect, craving, and resistance to smoking, as well as an assessment of quit motivation. We found that after controlling for trait impulsivity, participants who introspected on craving and affect showed higher delay discounting, irrespective of cue type, but we found no effect of response condition on subsequent craving (e.g., craving reactivity). We also found that motivation to quit interacted with experimental conditions to predict state craving and state resistance to smoking. Although asking about craving during cue exposure did not increase later craving, it resulted in greater delaying of discounted rewards. Overall, our findings suggest the need to further assess the implications of introspection and motivation on behavioral outcomes of cue exposure.

Magnitude and duration of cue-induced craving for marijuana in volunteers with cannabis use disorder

AIMS

Evaluate magnitude and duration of subjective and physiologic responses to neutral and marijuana (MJ)-related cues in cannabis dependent volunteers.

METHODS

33 volunteers (17 male) who met DSM-IV criteria for Cannabis Abuse or Dependence were exposed to neutral (first) then MJ-related visual, auditory, olfactory and tactile cues. Mood, drug craving and physiology were assessed at baseline, post-neutral, post-MJ and 15-min post MJ cue exposure to determine magnitude of cue- responses. For a subset of participants (n=15; 9 male), measures of craving and physiology were collected also at 30-, 90-, and 150-min post-MJ cue to examine duration of cue-effects.

RESULTS

In cue-response magnitude analyses, visual analog scale (VAS) items craving for, urge to use, and desire to smoke MJ, Total and Compulsivity subscale scores of the Marijuana Craving Questionnaire, anxiety ratings, and diastolic blood pressure (BP) were significantly elevated following MJ vs. neutral cue exposure. In cue-response duration analyses, desire and urge to use MJ remained significantly elevated at 30-, 90- and 150-min post MJ-cue exposure, relative to baseline and neutral cues.

CONCLUSIONS

Presentation of polysensory MJ cues increased MJ craving, anxiety and diastolic BP relative to baseline and neutral cues. MJ craving remained elevated up to 150-min after MJ cue presentation. This finding confirms that carry-over effects from drug cue presentation must be considered in cue reactivity studies.

An examination of reactivity to craving assessment: craving to smoke does not change over the course of a multi-item craving questionnaire

INTRODUCTION

Self-report measures are typically used to assess drug craving, but researchers have questioned whether completing these assessments can elicit or enhance craving. Previous studies have examined cigarette craving reactivity and found null craving reactivity effects. Several methodological limitations of those studies, however, preclude definitive conclusions. The current study addresses limitations of previous studies and extends this area of research by using a large sample size to examine: (1) item-by-item changes in craving level during questionnaire completion, (2) craving reactivity as a function of craving intensity reflected in item content, (3) craving reactivity differences between nicotine dependent and nondependent smokers, and (4) potential reactivity across multiple sessions. This study also used a more comprehensive craving assessment (the 32-item Questionnaire on Smoking Urges; QSU) than employed in previous studies.

METHODS

Nicotine dependent and nondependent smokers (n=270; nicotine dependence determined by the Nicotine Addiction Taxon Scale) completed the QSU on six separate occasions across 12 weeks. Craving level was observed at the item level and across various subsets of items.

RESULTS

Analyses indicated that there was no significant effect of item/subset position on craving ratings, nor were there any significant interactions between item/subset position and session or level of nicotine dependence.

CONCLUSIONS

These findings indicate that, even with relatively sensitive procedures for detecting potential reactivity, there was no evidence that completing a craving questionnaire induces craving.

Impulsivity and cigarette craving among adolescent daily and occasional smokers

INTRODUCTION

Impulsivity is a multi-dimensional construct that is robustly related to cigarette smoking. While underlying factors that account for this relation are not well understood, craving has been proposed as a central mechanism linking impulsivity to smoking. In order to further refine our understanding of associations between impulsivity and cigarette craving, the current study examined the association between impulsivity and tonic and cue-elicited craving among a sample of adolescent smokers. We expected trait impulsivity would be positively associated with both tonic and cue-elicited craving, and that this relationship would be stronger among daily vs. occasional smokers.

METHODS

106 smokers (ages 16-20) completed the questionnaires and reported their cigarette craving prior to and immediately following presentation of each of three counterbalanced cue types: (a) in vivo smoking, (b) alcohol, and (c) neutral cue.

RESULTS

Impulsivity was positively associated with tonic craving for daily smokers (β=.38; p=.005), but not occasional smokers (β=.01; p=.95), with a significant impulsivity x smoker group interaction (β=1.31; p=.03). Impulsivity was unrelated to craving following smoking or alcohol cue, regardless of smoker group (all p's>.16).

CONCLUSIONS

Results suggest a moderated effect in which impulsivity is positively associated with tonic craving for daily smokers, but not occasional smokers. Tonic craving may serve as a mechanism linking impulsivity, smoking persistence, and nicotine dependence among daily smokers.

Smoker reactivity to cues: effects on craving and on smoking behavior

We assessed craving and smoking in response to smoking-relevant cues. Two hundred seven daily smokers viewed images related to 1 of 6 cue sets (cigarettes, positive and negative affect, alcohol, smoking prohibitions, and neutral cues) in separate sessions. Compared with neutral cues, cigarette cues significantly increased craving, and positive affect cues significantly decreased craving. When subjects were then allowed to smoke during continuing cue exposure, cues did not affect the likelihood of smoking or the amount smoked (number of cigarettes, number of puffs, puff time, or increased carbon monoxide). However, craving intensity predicted likelihood of smoking, latency to smoke, and amount smoked, with craving increases after cue exposure making significant independent contributions. Some craving effects were curvilinear, suggesting that they are subject to thresholds and might not be observed under some circumstances.

Delay discounting, locus of control, and cognitive impulsiveness independently predict tobacco dependence treatment outcomes in a highly dependent, lower socioeconomic group of smokers

Tobacco use disproportionately affects lower socioeconomic status (SES) groups. Current explanations as to why lower SES groups respond less robustly to tobacco control efforts and tobacco dependence treatment do not fully account for this disparity. The identification of factors that predict relapse in this population might help to clarify these differences. Good candidates for novel prognostic factors include the constellation of behaviors associated with executive function including self-control/impulsiveness, the propensity to delay reward, and consideration and planning of future events. This study examined the ability of several measures of executive function and other key clinical, psychological, and cognitive factors to predict abstinence for highly dependent lower SES participants enrolled in intensive cognitive-behavioral treatment for tobacco dependence. Consistent with predictions, increased discounting and impulsiveness, an external locus of control as well as greater levels of nicotine dependence, stress, and smoking for negative affect reduction predicted relapse. These findings suggest that these novel factors are clinically relevant in predicting treatment outcomes and suggest new targets for therapeutic assessment and treatment approaches.

Exposure to smoking cues: cardiovascular and autonomic effects

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

Counterbalancing in smoking cue research: a critical analysis

INTRODUCTION

Cue exposure research has been used to examine key issues in smoking research, such as predicting relapse, testing new medications, investigating the neurobiology of nicotine dependence, and examining reactivity among smokers with comorbid psychopathologies. Determining the order that cues are presented is one of the most critical steps in the design of these investigations. It is widely assumed that cue exposure studies should counterbalance the order in which smoking and control (neutral) cues are presented. This article examines the premises underlying the use of counterbalancing in experimental research, and it evaluates the degree to which counterbalancing is appropriate in smoking cue exposure studies.

METHODS

We reviewed the available literature on the use of counterbalancing techniques in human smoking cue exposure research.

RESULTS

Many studies counterbalancing order of cues have not provided critical analyses to determine whether this approach was appropriate. Studies that have reported relevant data, however, suggest that order of cue presentation interacts with type of cue (smoking vs. control), which raises concerns about the utility of counterbalancing. Primarily, this concern arises from potential carryover effects, in which exposure to smoking cues affects subsequent responding to neutral cues.

CONCLUSIONS

Cue type by order of cue interactions may compromise the utility of counterbalancing. Unfortunately, there is no obvious alternative that is optimal across studies. Strengths and limitations of several alternative designs are considered, and key questions are identified to advance understanding of the optimal conditions for conducting smoking cue exposure studies.

Prolonged duration of craving, mood, and autonomic responses elicited by cues and imagery in smokers: Effects of tobacco deprivation and sex

Increases in self-reported craving and changes in autonomic functioning are reliably elicited when smokers are exposed to tobacco-related stimuli compared with neutral stimuli. However, few studies have reported the time course of cue-elicited craving or have directly compared the effectiveness of smoking cues versus imagery to evoke a craving response. In addition to these two issues, we investigated the influence of tobacco deprivation and sex on craving, mood, and autonomic responses. Sixty cigarette smokers (30 men, 30 women) were tested in two counterbalanced sessions, one after overnight tobacco deprivation and one during ad libitum smoking. At each session, participants were exposed to four randomized experimental trials: smoking imagery, neutral imagery, smoking cues, and neutral cues. Tobacco craving and mood were assessed repeatedly and physiological measures were recorded continuously for 30 min after imagery or cue exposure. Compared with neutral trials, smoking cues and smoking imagery reliably increased tobacco craving, negative mood, heart rate, and blood pressure and decreased positive mood ratings. Changes were observed immediately after cue and imagery presentation and remained unchanged for 30 min. Responding was greater in the nondeprived condition, and cues elicited more robust responding than imagery for most measures. Women responded more robustly to smoking cues only in the nondeprived condition, whereas imagery evoked greater responses in men during both conditions. These findings provide new data on the time course, magnitude, and tobacco deprivation effects on elicited craving. Sex differences were dependent on stimulus type and deprivation condition.

Validity of the 12-item French version of the Tobacco Craving Questionnaire in treatment-seeking smokers

INTRODUCTION

The French version of the Tobacco Craving Questionnaire (FTCQ) is a valid and reliable 47-item self-report instrument that assesses tobacco craving in four factors: emotionality, expectancy, compulsivity, and purposefulness. For use in research and clinical settings, we constructed a 12-item version of the FTCQ (FTCQ-12).

METHOD

The FTCQ-12 was administered to treatment-seeking French smokers (n = 310) enrolled in the Adjustment of DOses of NIcotine in Smoking Cessation (ADONIS) trial. We conducted confirmatory factor analysis (CFA) and examined congruence in factor loadings between the FTCQ and FTCQ-12 to determine the validity and reliability of the FTCQ-12. Measures of tobacco craving, withdrawal, smoking patterns, and smoking history were included to explore the concurrent validity of the FTCQ-12. We used craving scores to distinguish participants who were highly dependent on nicotine from those less dependent on nicotine.

RESULTS

CFA indicated excellent fit for a four-factor model, with congruence coefficients indicating moderate similarity in factor patterns and loadings between the FTCQ and FTCQ-12. Individual factors of the FTCQ-12 correlated positively with smoking history and withdrawal variables. Participants who were highly dependent on nicotine were nearly six times more likely to score >5 on the General Craving Score (maximum: 7) than those less dependent on nicotine.

DISCUSSION

Findings suggest that the FTCQ-12 measures the same four factors as the FTCQ and TCQ, and these four constructs have unique properties. The FTCQ-12 yields valid and reliable indices of tobacco craving and has potential clinical utility for rapid assessment of tobacco craving in smokers seeking treatment.

The impact of chronic bupropion on plasma cotinine and on the subjective effects of ad lib smoking: a randomized controlled trial in unmotivated smokers

Bupropion is an efficacious non-nicotine medication for smoking cessation; however, its cessation-mediating mechanism is unclear. This randomized, placebo-controlled trial examined the effect of bupropion SR (300 mg/day for 6 weeks) on plasma cotinine and on the subjective effects of smoking in 24 current daily smokers who were not trying to quit or reduce smoking. Subjective effects of smoking, as well as cue-elicited responses were assessed at bi-weekly experimental sessions using validated scales. Several indices of cigarette consumption were measured. Plasma cotinine decreased from 280 (+/-133) microg/l at baseline to 205 (+/-108) microg/l at end of treatment in the bupropion group (p=0.036), but no significant change was found in the placebo group. Daily cigarette count and puff topography did not significantly change in either group. In contrast to placebo, bupropion increased post-smoking satiety (p=0.045). Both groups reported higher craving (p=0.025) and withdrawal (p=0.014) after exposure to smoking-related pictures, compared to neutral pictures. This biased reactivity was not significantly affected by treatment condition (p>0.1). Therefore, bupropion does not appear to impact the smokers' response to conditioned smoking-related cues but influences the unconditioned subjective effects of smoking in unmotivated smokers. This study is among the first to systematically investigate the effect of chronic bupropion administration, free from the confounding effect of the smoker's motivation to quit smoking.

Clinical and laboratory assessment of the subjective experience of drug craving

Measures of subjective drug craving - often defined as the experience of an intense or compelling urge or desire - may be used to predict relapse, evaluate psychological and pharmacological treatments, and test theories of addiction and craving. This review summarizes both direct self-report questionnaires and indirect behavioral, physiological and reaction time measures designed to assess craving for alcohol, amphetamines, cocaine, heroin, marijuana, and tobacco. Multi-item questionnaires have typically been based on one of four underlying conceptualizations of addiction or craving (obsessive-compulsive, approach-avoidance, multi-dimensional, intensity-frequency-duration). Most multi-item self-report questionnaires have high internal consistency, correlate significantly with single-item craving ratings, and demonstrate several aspects of construct validity. Proposed indirect or proxy measures of craving include drug dreams, speed of drug consumption, willingness to work for drug access, selection of monetary rewards over drug access, psychophysiological reactivity, and attentional bias to drug cues. These proxy measures of craving are presumed to obviate self-report biases, to be less subject to conscious self-control, and to reflect craving which the person may not be able to articulate; however, there have been too few demonstrations of their validity and they have too many practical limitations to supplant self-report measures of craving at this time.

Reliability and validity of a short form of the Marijuana Craving Questionnaire

BACKGROUND

The Marijuana Craving Questionnaire (MCQ) is a valid and reliable, 47-item self-report instrument that assesses marijuana craving along four dimensions: compulsivity, emotionality, expectancy, and purposefulness. For use in research and clinical settings, we constructed a 12-item version of the MCQ by selecting three items from each of the four factors that exhibited the greatest within-factor internal consistency (Cronbach's alpha coefficient).

METHODS

Adult marijuana users (n=490), who had made at least one serious attempt to quit marijuana use but were not seeking treatment, completed the MCQ-Short Form (MCQ-SF) in a single session.

RESULTS

Confirmatory factor analysis of the MCQ-SF indicated good fit with the 4-factor MCQ model, and the coefficient of congruence indicated moderate similarity in factor patterns and loadings between the MCQ and MCQ-SF. Homogeneity (unidimensionality and internal consistency) of MCQ-SF factors was also consistent with reliability values obtained in the initial validation of the MCQ.

CONCLUSIONS

Findings of psychometric fidelity indicate that the MCQ-SF is a reliable and valid measure of the same multidimensional aspects of marijuana craving as the MCQ in marijuana users not seeking treatment.

Reliability and validity of a Short Form of the Tobacco Craving Questionnaire

The Tobacco Craving Questionnaire (TCQ) is a valid and reliable 47-item self-report instrument that assesses tobacco craving in four dimensions: emotionality, expectancy, compulsivity, and purposefulness. For use in research and clinical settings, we constructed a 12-item version of the TCQ by selecting three items from each of the four factors that exhibited optimal within-factor reliability (Cronbach's alpha coefficient) and inter-item correlation. Smokers (N = 196) completed the TCQ-Short Form (TCQ-SF) after overnight tobacco deprivation and on a separate day during ad libitum smoking. Confirmatory factor analyses indicated acceptable model fit for a 4-factor model, with congruence coefficients suggesting high to very high similarity in factor patterns and magnitude of factor loadings between the TCQ and TCQ-SF in both conditions. Scores on each factor were significantly greater after tobacco deprivation than ad libitum smoking, were associated with measures of tobacco withdrawal, and varied with degree of nicotine dependence. Cronbach's alpha coefficients and average inter-item correlations were similar in both conditions and were consistent with reliability values obtained in the initial validation of the TCQ. Test-retest correlation coefficients were also similar to those found in a previous study. These findings suggest that the TCQ-SF is as valid and reliable as the 47-item TCQ in measuring tobacco craving.

Carry-over effects of smoking cue exposure on working memory performance

The present study investigated the effects of drug cue exposure on working memory performance in cigarette smokers. Adult smokers (N = 23) deprived for 12 hr performed a working memory task during which they were exposed to three types of task-irrelevant stimuli: Pictures containing smoking related-content, pictures devoid of smoking content, and a fixation cross. Consistent with prior research, we found that drug cue exposure affected the processing of subsequent items (i.e., carry-over effects). Specifically, we found that working memory performance was worse on trials containing neutral pictures preceded by trials containing smoking cues compared with performance on trials containing neutral pictures preceded by trials not containing smoking-related stimuli. Previously observed effects of smoking cue exposure on cognitive processing were replicated but only after removing trials subject to carry-over effects. These results replicate and extend previous research demonstrating similar effects and highlight the significant methodological and conceptual implications of carry-over effects.

Complex interactions between nicotine and nonpharmacological stimuli reveal multiple roles for nicotine in reinforcement

RATIONALE

Although considerable progress has been made, we do not yet fully understand the behavioral and neurobiological basis of nicotine reinforcement, and without this knowledge, treatment strategies aimed at reducing smoking remain deficient.

OBJECTIVES

This review describes an original perspective on nicotine reinforcement, which arises from substantial evidence of complex interactions between nicotine and nonpharmacological stimuli. We hypothesize that nicotine reinforcement derives from at least two sources: (1) primary reinforcement, an action that requires response-dependent drug administration and is capable of conveying secondary reinforcing effects on associated stimuli, and (2) the reinforcement-enhancing effect of nicotine, which directly enhances behavior maintained by salient nonnicotine stimuli and does not require a contingent relationship between drug administration and reinforced operant responding. Although novel for nicotine, this hypothesis has origins in an extensive literature on the reinforcing effects of psychostimulants. Empirical support for this hypothesis, based largely on animal models of reinforcement, will be presented.

CONCLUSIONS

Animal models of drug reinforcement have evolved to reflect our growing awareness of the multidimensional nature of drug dependence in humans. Investigating the interaction between nicotine and nonpharmacological stimuli within the context of the drug self-administration paradigm in rats has generated new insights into the paradox of how nicotine, an apparently weak primary reinforcer, can sustain the robust behavior observed in self-administration and in smoking. The hypothesis presented in this paper--that nicotine acts as both a primary reinforcer and an enhancer of other nonnicotine reinforcers--provides important direction for future investigations into the neurobiology of nicotine reinforcement and treatments for smoking cessation.