Smoking patterns and stimulus control in intermittent and daily smokers

Intermittent smokers (ITS) - who smoke less than daily - comprise an increasing proportion of adult smokers. Their smoking patterns challenge theoretical models of smoking motivation, which emphasize regular and frequent smoking to maintain nicotine levels and avoid withdrawal, but yet have gone largely unexamined. We characterized smoking patterns among 212 ITS (smoking 4-27 days per month) compared to 194 daily smokers (DS; smoking 5-30 cigarettes daily) who monitored situational antecedents of smoking using ecological momentary assessment. Subjects recorded each cigarette on an electronic diary, and situational variables were assessed in a random subset (n = 21,539 smoking episodes); parallel assessments were obtained by beeping subjects at random when they were not smoking (n = 26,930 non-smoking occasions). Compared to DS, ITS' smoking was more strongly associated with being away from home, being in a bar, drinking alcohol, socializing, being with friends and acquaintances, and when others were smoking. Mood had only modest effects in either group. DS' and ITS' smoking were substantially and equally suppressed by smoking restrictions, although ITS more often cited self-imposed restrictions. ITS' smoking was consistently more associated with environmental cues and contexts, especially those associated with positive or "indulgent" smoking situations. Stimulus control may be an important influence in maintaining smoking and making quitting difficult among ITS. © 2014 Shiffman et al

Increased Resting-State Functional Connectivity in Obese Adolescents; A Magnetoencephalographic Pilot Study

BACKGROUND: Obesity is not only associated with metabolic abnormalities, but also with cognitive dysfunction and changes in the central nervous system. The present pilot study was carried out to investigate functional connectivity in obese and non-obese adolescents using magnetoencephalography (MEG). METHODOLOGY/PRINCIPAL FINDINGS: Magnetoencephalographic recordings were performed in 11 obese (mean BMI 38.8+/-4.6 kg/m(2)) and 8 lean (mean BMI 21.0+/-1.5 kg/m(2)) female adolescents (age 12-19 years) during an eyes-closed resting-state condition. From these recordings, the synchronization likelihood (SL), a common method that estimates both linear and non-linear interdependencies between MEG signals, was calculated within and between brain regions, and within standard frequency bands (delta, theta, alpha1, alpha2, beta and gamma). The obese adolescents had increased synchronization in delta (0.5-4 Hz) and beta (13-30 Hz) frequency bands compared to lean controls (P(delta total) = 0.001; P(beta total) = 0.002). CONCLUSIONS/SIGNIFICANCE: This study identified increased resting-state functional connectivity in severe obese adolescents. Considering the importance of functional coupling between brain areas for cognitive functioning, the present findings strengthen the hypothesis that obesity may have a major impact on human brain function. The cause of the observed excessive synchronization is unknown, but might be related to disturbed motivational pathways, the recently demonstrated increase in white matter volume in obese subjects or altered metabolic processes like hyperinsulinemia. The question arises whether the changes in brain structure and communication are a dynamic process due to weight gain and whether these effects are reversible or not

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

Journal ArticleResearch Support, Non-U.S. Gov'tCopyright © The Author(s) 2011.RATIONALE: Impulsivity has long been known as a risk factor for drug dependence, but the mechanisms underpinning this association are unclear. Impulsivity may confer hypersensitivity to drug reinforcement which establishes higher rates of instrumental drug-seeking and drug-taking behaviour, or may confer a propensity for automatic (non-intentional) control over drug-seeking/taking and thus intransigence to clinical intervention. METHOD: The current study sought to distinguish these two accounts by measuring Barratt Impulsivity and craving to smoke in 100 smokers prior to their completion of an instrumental concurrent choice task for tobacco (to measure the rate of drug-seeking) and an ad libitum smoking test (to measure the rate of drug-taking-number of puffs consumed). RESULTS: The results showed that impulsivity was not associated with higher rates of drug-seeking/taking, but individual differences in smoking uptake and craving were. Rather, nonplanning impulsivity moderated (decreased) the relationship between craving and drug-taking, but not drug-seeking. CONCLUSIONS: These data suggest that whereas the uptake of drug use is mediated by hypervaluation of the drug as an instrumental goal, the orthogonal trait nonplanning impulsivity confers a propensity for automatic control over well-practiced drug-taking behaviour.MR

Review article: pharmacotherapy for alcohol dependence - the why, the what and the wherefore

BACKGROUND: The development of alcohol dependence is associated with significant morbidity and mortality. For the majority of affected people the most appropriate goal, in terms of drinking behaviour, is abstinence from alcohol. Psychosocial intervention is the mainstay of the treatment but adjuvant pharmacotherapy is also available and its use recommended. AIM: To provide an updated analysis of current and potential pharmacotherapeutic options for the management of alcohol dependence. In addition, factors predictive of therapeutic outcome, including compliance and pharmacogenetics, and the current barriers to treatment, including doctors' unwillingness to prescribe these agents, will be explored. METHODS: Relevant papers were selected for review following extensive, language- and date-unrestricted, electronic and manual searches of the literature. RESULTS: Acamprosate and naltrexone have a substantial evidence base for overall efficacy, safety and cost-effectiveness while the risks associated with the use of disulfiram are well-known and can be minimised with appropriate patient selection and supervision. Acamprosate can be used safely in patients with liver disease and in those with comorbid mental health issues and co-occurring drug-related problems. A number of other agents are being investigated for potential use for this indication including: baclofen, topiramate and metadoxine. CONCLUSION: Pharmacotherapy for alcohol dependence has been shown to be moderately efficacious with few safety concerns, but it is substantially underutilised. Concerted efforts must be made to remove the barriers to treatment in order to optimise the management of people with this condition

RED WOLF CONSERVATION IN THE FACE OF CLIMATE CHANGE

The critically endangered red wolf is the focus of a long-standing recovery effort. How climate change might affect it is unknown. Sea-level rise will greatly restrict its current habitat site. Several other threats pressure it. I used three GIS approaches: (1) using site prioritization variables alone, (2) using Model 1 variables and projected sea-level rise, and (3) using Model 2 variables and projected urbanization. I ranked potential reintroduction sites on their suitability scores from each model, compared results between models, and made recommendations to management. The results differed between models. The best sites shifted inland in Model 2 and towards rural areas in Model 3. This indicates that these variables are important in determining site suitability. Top sites from Models 2 and 3 had slightly lower suitability scores, but I expect them to be more sustainable in the future. The suitability of individual variables (e.g., habitat type, prey abundance) differed between sites, but top sites in all 3 scenarios had high overall suitability scores. The U.S. Fish and Wildlife Service (USFWS) should prioritize reintroduction efforts at a combination of sites identified here as Moderately to Highly Suitable (scores of 16.5 or above) in all three models, and should make specific plans according to the strengths and weaknesses that I identified for each site. This will provide better conditions for the survival of the species, ecosystem health, and, importantly, cost-effectiveness. As natural apex predators, red wolves have a unique ability to help restore health and balance to our ecosystems of the southeast. This will benefit wildlife, natural systems, and people

A physiological analysis of smoking urges: Imagery, cue-reactivity, and nicotine deprivation

This experiment compared imagery and in vivo cue-exposure techniques as methods of manipulating smoking urges in a laboratory setting. Subjects, 100 daily cigarette smokers (50 males, 50 females), attended two experimental sessions separated by an interval of 6 hours. Each experimental session included a two-way within subjects manipulation of trial type in which two levels of urge cues (urge vs. neutral) were completely crossed with two urge induction methods (imagery vs. in vivo) with three presentations of each trial type. Measures taken during each trial included heart rate, skin conductance, finger temperature, corrugator EMG, and zygomatic EMG. Immediately after each trial subjects rated their level of urges, positive and negative affect, and trial vividness. Half of the subjects were assigned to abstain from smoking over the inter-session interval in order to examine the effects of nicotine deprivation on measures of urge reactivity. Results indicated that imagery and in vivo methods were equally effective at eliciting high levels of self-reported urges to urge-relevant material. Physiological responses also discriminated urge-relevant and neutral trials, though the patterns of physiological responding elicited by the two urge induction methods were notably dissimilar. There was little relationship between verbal urge reporting and physiological responding, and several non-physiological measures were predictive of post-trial urge report. The implications of these findings for several urge theories are discussed, and suggestions for further research in this area are provided