Conceptualizing craving : extrapolations from consciousness studies

The key definitional elements of the concept of craving remain highly contentious amongst addiction researchers. We argue that attempts to operationalize the craving construct may benefit from the conceptual and methodological advances that have occurred in the field of consciousness studies. Specifically, it is contended that the concept of craving cannot be fully articulated in the absence of a consideration of Husserl's notion of the intentional structure of human consciousness and related concepts such as phenomenology, discrete states of consciousness and altered states of consciousness. Extrapolating from the consciousness studies literature, we formulate numerous suggestions for future research intended to facilitate the operationalization of craving experiences.

Cue reward salience predicts craving in response to alcohol cues

Many studies have shown that regular drinkers react to alcohol-related stimuli (i.e., cue reactivity) with a variety of appetitive responses, in particular, increased urge to drink. Recent research has focused on accounting for variability in responses to alcohol-related stimuli by examining drinking histories and personality. The aim of the current study was to extend this line of work by investigating the role of reinforcement expectancies (‘cue reward salience’) in alcohol cue reactivity research. In this study, ‘cue reward salience’ refers to the notion that appetitive responses will only ensue if the individual finds the stimulus to be equal to or more rewarding than initial expectations. Sixty-one regular drinkers completed a standard cue reactivity assessment whereby reactions (i.e., urge to drink and affect) to the sight, smell and taste of alcohol are measured and compared to a control condition. Results indicated significant increases in positive urge to drink but no changes in affect. Analyses revealed that drinking level and trait reward sensitivity were significant predictors of the urge to drink response. In addition, ‘cue reward salience’ accounted for significant additional variance in predicting urge to drink alcohol. Discussion focuses on the importance of measuring reinforcement expectancies when conducting cue reactivity studies.

Reduction of vividness and associated craving in personalized food imagery

This study aimed to extend recent experimental work on the efficacy of visuo-spatial working memory-based techniques for reducing food cravings by adopting a more naturalistic methodology. Fifty undergraduate women formed images of their favorite foods while performing a visuo-spatial task across six successive trials. Vividness and craving intensity were rated for each food image. Concurrent visuo-spatial processing reduced the vividness of, and craving reactivity to, personally relevant food images. Forehead tracking, a novel self-administered task, proved to be as effective in reducing vividness and craving ratings as the established visuo-spatial working memory laboratory tasks of eye movements, dynamic visual noise, and spatial tapping, and thus presents a simple, accessible technique potentially applicable in the home environment. All four tasks maintained their reducing effect over multiple trials. Individual differences in imaging ability and habitual food craving did not impact upon their effectiveness, indicating that visuo-spatial tasks can be successfully used to reduce food cravings across a range of people.

The value of impulsivity to define subgroups of addicted individuals differing in personality dysfunction, craving, psychosocial adjustment, and wellbeing: A latent class analysis

High impulsivity is common to substance and gambling addictions. Despite these commonalities, there is still substantial heterogeneity on impulsivity levels within these diagnostic groups, and variations in impulsive levels predict higher severity of symptoms and poorer outcomes. We addressed the question of whether impulsivity scores can yield empirically driven subgroups of addicted individuals that will exhibit different clinical presentations and outcomes. We applied latent class analysis (LCA) to trait (UPPS-P impulsive behavior scale) and cognitive impulsivity (Stroop and d2 tests) scores in three predominantly male addiction diagnostic groups: Cocaine with Personality Disorders, Cocaine Non-comorbid, and Gambling and analyzed the usefulness of the resulting subgroups to differentiate personality beliefs and relevant outcomes: Craving, psychosocial adjustment, and quality of life. In accordance with impulsivity scores, the three addiction diagnostic groups are best represented as two separate classes: Class 1 characterized by greater trait impulsivity and poorer cognitive impulsivity performance and Class 2 characterized by lower trait impulsivity and better cognitive impulsivity performance. The two empirically derived classes showed significant differences on personality features and outcome variables (Class 1 exhibited greater personality dysfunction and worse clinical outcomes), whereas conventional diagnostic groups showed non-significant differences on most of these measures. Trait and cognitive impulsivity scores differentiate subgroups of addicted individuals with more versus less severe personality features and clinical outcomes.

Examining the affective tone of alcohol craving in young drinkers

An abundance of research has examined craving and affective responses to alcohol; however, minimal emphasis has been placed on the relationship between craving and affective states at specific time points of alcohol consumption. Fifty-nine university students (28 light drinkers, 31 heavy drinkers) completed assessments of craving, and positive and negative affect at baseline (Time 1), immediately following consumption of a standard drink of alcohol (Time 2), and 20 min post consumption (Time 3). In light drinkers, craving was positively correlated with positive affect at all 3 time points. In heavy drinkers, craving was only correlated with positive affect at Time 2. There were no associations between craving and negative affect at any time point in either group. A subsequent profile analysis revealed parallel profiles of craving and positive affect over time in light drinkers, but not heavy drinkers. At 20 min post alcohol consumption, a moderated regression showed that the relationship between craving and positive affect weakened as level of alcohol use increased. These findings suggest that craving is positively associated with positive affect in light drinkers, but as levels of drinking escalate, this association dissipates.

Reactivity to alcohol-related cues: relationship among cue type, motivational processes, and personality

This study examined the relationship between personality traits implicated in the drinking literature (i.e., sensation seeking and anxiety) and reactivity to 2 different alcohol cues. The opportunity to consume alcohol was manipulated, and differences in urge and affective reactivity were assessed. Gray’s (1987) model of impulsive sensation seeking and anxiety was adopted to investigate relationships between personality and responses to the appetitive (consumption) and aversive (no consumption, nonrewarding) alcohol cues in 40 regular social drinkers. The consumption cue produced increases in appetitive motivation and positive correlations with sensation-seeking traits. The no-consumption cue produced increases in aversive motivation and positive correlations with anxiety-related traits. It was concluded that Gray’s model of impulsive sensation seeking and anxiety may provide a useful framework for examining the personality correlates of cue reactivity to different cues.

Reinforcement sensitivity theory : a paradigm for understanding the motivational processes underlying alcohol use

Provides an examination of the processes which motivate individuals to drink alcohol. It was found that heavier drinkers are highly sensitive to reward yet more likely to experience negative affect, both generally, and in response to alcohol-related cues. Based on these findings a model focusing on the links between personality, mood and craving for alcohol was developed.

Nail-biting stuff? The effect of N-acetyl cysteine on nail-biting

N-acetyl cysteine (NAC) is a widely available nutraceutical with a variety of actions. As a precursor of cysteine and glutathione, it has antioxidant properties that may impact on mood and contribute to an effect on impulsivity and obsessive behaviour. Via its additional effect on glutamate via the cystine-glutamate exchange system, NAC has been shown to mediate impulsivity in preclinical models of addiction, reduce craving, and cue extinction. Further, by boosting glutathione, NAC acts as a potent antioxidant and has been shown in two positive, large-scale randomized placebo-controlled trials to affect negative symptoms in schizophrenia and depression in bipolar disorder. We describe three cases in which its actions specifically on nail-biting and associated anxiety may offer a potential treatment. The spontaneous findings are reported as part of an ongoing treatment trial examining the utility of NAC in bipolar disorder. Its actions, if robustly replicated, also point to potential treatment targets in glutathione or glutamate pathways in the brain.

Smokers and ex-smokers reaction to anti-smoking advertising : a mixed methods approach

Anti-smoking advertising is a central component of modern public health policy. Nevertheless, some smokers have reported that viewing anti-smoking advertising provokes intense nicotine craving. Anti-smoking advertising frequently features images of cigarettes and of individuals smoking. However, research indicates that images of tobacco paraphernalia may induce cravings in individuals addicted to nicotine. The effects of the presence of smoking cues in anti-smoking advertising were considered in the present study. Smokers and ex-smokers (N=63) were randomly assigned to view an anti-smoking advertisement or to complete a control task. Urge to smoke was measured pre- and post-test. Qualitative responses to anti-smoking advertising were also elicited from all participants in the intervention groups. According to both qualitative and quantitative data analyses viewing anti-smoking advertising, even with images of smoking related paraphernalia, led to decreases in craving amongst smokers. Ex-smokers experienced no change in quantitatively measured craving after viewing anti-smoking advertising. These findings are inconsistent with findings from studies using neutral or positive smoking cues. Qualitative data shows that no smokers or ex-smokers who viewed anti-smoking advertising reported an increase in tobacco craving as a result of viewing the campaign. Implications of these findings for future research and anti-smoking campaigns are discussed.

N-acetylcysteine for therapy-resistant tobacco use disorder: a pilot study

Introduction N-Acetylcysteine (NAC) may have efficacy in treating tobacco use disorder (TUD) by reducing craving and smoking reward. This study examines whether treatment with NAC may have a clinical efficacy in the treatment of TUD. Methods A 12-week double blind randomized controlled trial was conducted to compare the clinical efficacy of NAC 3 g/day versus placebo. We recruited 34 outpatients with therapy resistant TUD concurrently treated with smoking-focused group behavioral therapy. Participants had assessments of daily cigarette use (primary outcome), exhaled carbon monoxide (COEXH) (secondary outcome), and quit rates as defined by COEXH<6 ppm. Depression was measured with the Hamilton Depression Rating Scale (HDRS). Data were analyzed using conventional and modified intention-to-treat endpoint analyses. Results NAC treatment significantly reduced the daily number of cigarettes used (Δ mean±SD = -10.9 ± 7.9 in the NAC-treated versus -3.2 ± 6.1 in the placebo group) and COEXH (Δ mean± SD = -10.4 ± 8.6 ppm in the NAC-treated versus -1.5 ± 4.5 ppm in the placebo group); 47.1% of those treated with NAC versus 21.4% of placebo-treated patients were able to quit smoking as defined by COEXH<6 ppm. NAC treatment significantly reduced the HDRS score in patients with tobacco use disorder. Conclusions These data show that treatment with NAC may have a clinical efficacy in TUD. NAC combined with appropriate psychotherapy appears to be an efficient treatment option for TUD.

Design and conduct of a pragmatic randomized controlled trial to enhance smoking-cessation outcomes with exercise: The Fit2Quit study

Background: Most smokers want to stop smoking and many try to quit. However abstinence rates are low and most smokers do not manage to abstain for even a week. Relapse to smoking can be related to the occurrence of tobacco withdrawal symptoms (e.g., sleep disturbance, irritability, and craving) and weight gain. If regular exercise mitigates these effects it could have potential as an aid to smoking cessation. The aim of the Fit2Quit study is to determine the effects of a home and community-based exercise intervention on smoking abstinence at six months when used as an adjunct to usual care (telephone smoking-cessation counseling and nicotine replacement therapy; NRT). Methods/design: A prospective parallel two-arm randomized controlled trial. Participants (n = 1400, 700 per arm) will be randomized to a structured home and community-based exercise program plus usual care (behavioral counseling and NRT) or to usual-care alone. It is targeted that at least 25% of the sample will be of Mori ethnicity (New Zealand indigenous). Outcomes to be measured using intention-to-treat analysis include: seven-day point prevalence of smoking abstinence verified by salivary cotinine (primary outcome); 6 months continuous abstinence; body mass index (BMI); cardio-respiratory fitness; physical activity levels; and cost effectiveness. Discussion: The Fit2Quit study is an example of a large, pragmatic randomized controlled trial in a community setting. Specific components of the exercise intervention are outlined in detail. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12609000637246.

A potential role for N-acetylcysteine in the management of methamphetamine dependence

Methamphetamine dependence is a growing problem in Australia and globally. Currently, there are no approved pharmacotherapy options for the management of methamphetamine dependence. N-acetylcysteine is one potential pharmacotherapy option. It has received growing attention as a therapy for managing addictions because of its capacity to restore homeostasis to brain glutamate systems disrupted in addiction and thereby reduce craving and the risk of relapse. N-acetylcysteine also has antioxidant properties that protect against methamphetamine-induced toxicity and it may therefore assist in the management of the neuropsychiatric and neurocognitive effects of methamphetamine. This commentary overviews the actions of N-acetylcysteine and evidence for its efficacy in treating addiction with a particular focus on its potential utility for methamphetamine dependence. We conclude that the preliminary evidence indicates a need for full-scale trials to definitively establish whether N-acetylcysteine has a therapeutic benefit and the nature of this benefit, for managing methamphetamine dependence.