Impact of CYP2A6 Activity on Nicotine Reinforcement and Cue-Reactivity in Daily Smokers.

Introduction: Variation in CYP2A6, the primary enzyme responsible for nicotine metabolism, is associated with nicotine dependence, cigarette consumption, and abstinence outcomes in smokers. The impact of CYP2A6 activity on nicotine reinforcement and tobacco cue-reactivity, mechanisms that may contribute to these previous associations, has not been fully evaluated.

Aims And Methods: CYP2A6 activity was indexed using 3 genetic approaches in 104 daily smokers completing forced-choice and cue-induced craving tasks assessing nicotine reinforcement and tobacco cue-reactivity, respectively.

Significant association of nicotine reinforcement and cue reactivity: a translational study in humans and rats.

Relapse is common amongst smokers attempting to quit and tobacco cue-induced craving is an important relapse mechanism. Preclinical studies commonly use cue-induced reinstatement of nicotine seeking to investigate relapse neurobiology. Previous research suggests dependence severity and nicotine intake history affect smoking resumption and cue-induced reinstatement of nicotine seeking.

The CB1R rs2023239 receptor gene variant significantly affects the reinforcing effects of nicotine, but not cue reactivity, in human smokers.

Introduction: The cannabinoid CB1 receptor (CB1R) has been shown in preclinical studies to be involved in nicotine reinforcement and relapse-like behavior. The common single nucleotide polymorphism (SNP) rs2023239 may code for an alternative CB1R protein, alter CB1R expression, and be involved in nicotine dependence. To date, no study has explored the relationship between this SNP in CB1R and specific phenotypes of nicotine dependence.

Exploring the role of the Ser9Gly (rs6280) Dopamine D3 receptor polymorphism in nicotine reinforcement and cue-elicited craving.

Preclinical studies show that the dopamine D3 receptor (D3R) is involved in the reinstatement of drug seeking and motivation for drugs of abuse. A D3R gene variant, Ser9Gly (rs6280) has been linked to nicotine dependence, yet the mechanisms underlying its involvement in nicotine dependence is unclear. This study investigated the relationship between the Ser9Gly variant and measures of both nicotine reinforcement and cue-elicited craving.

Testing the PPAR hypothesis of tobacco use disorder in humans: A randomized trial of the impact of gemfibrozil (a partial PPARα agonist) in smokers.

Unlabelled: Previous pre-clinical studies demonstrated a promising role of alpha-type peroxisome proliferator-activated receptors (PPARα) agonists in decreasing nicotine self-administration and nicotine-seeking behavior in animals. Our goal was to investigate the potential of gemfibrozil, a PPARα agonist, on reducing tobacco smoking in humans.

Methods: This was a double-blind, placebo-controlled, crossover study evaluating the effects of gemfibrozil (1200 mg/day) on smoking in 27 treatment-seeking smokers.

Nicotine Intake in Pregnant Smokers and a General Population of Smokers.

Objective: The purpose of this study was to assess whether pregnant smokers have the same nicotine intake from cigarettes as a general population of smokers and whether the known lower daily cigarette consumption among pregnant smokers is associated with higher nicotine intake among pregnant smokers.

Method: The study was a cross-sectional comparison of pregnant smokers and a general population of smokers in smoking cessation clinics. Participants were treatment-seeking pregnant (n = 476), nonpregnant female (n = 116), and male (n = 195) smokers who participated in two independent smoking cessation trials.

Cigarette Smoking During Pregnancy: Do Complete Abstinence and Low Level Cigarette Smoking Have Similar Impact on Birth Weight?

Objectives: Despite awareness of negative health outcomes associated with smoking, pregnant smokers might reduce their tobacco consumption thinking that a low smoking rate reduces smoking-related negative birth outcomes. We aimed to assess in a clinical sample whether there is a smoking rate that would not impact on birth weight (BW).

Methods: Pregnant smokers ≥18 years, gestational age of 9-20 weeks of amenorrhea, motivated to quit smoking, smoking ≥5 cigarettes/day (cpd) and their newborns (381 singleton, live births) were included in this secondary analysis of a French smoking cessation trial.

Antipsychotic Treatment and Tobacco Craving in People With Schizophrenia.

Objective: Nicotine dependence is high in schizophrenia, and craving is known to impact relapse during quit attempts.

Methods: We compared tobacco craving in smokers with schizophrenia treated with different antipsychotics.

Results: Mean craving scores were lowest in participants receiving first-generation antipsychotics, although these differences were not statistically significant.

Predictors of the Perception of Smoking Health Risks in Smokers With or Without Schizophrenia.

Objective: This study sought to examine the predictors of health risk perception in smokers with or without schizophrenia.

Methods: The health risk subscale from the Smoking Consequences Questionnaire was dichotomized and used to measure health risk perception in smokers with (n = 67) and without schizophrenia (n = 100). A backward stepwise logistic regression was conducted using variables associated at the bivariate level to determine multivariate predictors.

Craving and Withdrawal Symptoms During Smoking Cessation: Comparison of Pregnant and Non-Pregnant Smokers.

Although pregnant smokers are aware of the negative peri- and postnatal health consequences of smoking, the cessation rate in pregnancy is low, raising the question of why pregnant smokers have difficulty quitting. Reasons might be that pregnant smokers experience more intense craving and withdrawal symptoms than non-pregnant smokers. We compared craving and withdrawal in 306 pregnant smokers versus 93 non-pregnant women using data from two smoking cessation trials.

Black Cigarette Smokers Report More Attention to Smoking Cues Than White Smokers: Implications for Smoking Cessation.

Introduction: Black cigarette smokers have lower rates of smoking cessation compared with Whites. However, the mechanisms underlying these differences are not clear. Many Blacks live in communities saturated by tobacco advertisements.

Cross validation of the prognostic and diagnostic utility of tobacco craving in a general and a pregnant sample of treatment-seeking smokers.

Background: Valid and reliable brief measures of tobacco craving are necessary for research and clinical purposes. However, comparisons of the utility of single-item and brief multidimensional craving measures are scarce.

Methods: We analyzed two tobacco craving measures, the French versions of the 12-item Tobacco Craving Questionnaire (FTCQ-12) and the single craving item on the Minnesota Nicotine Withdrawal Scale, in pregnant and non-pregnant (females and males) French smokers from two independent smoking cessation trials.

A Comparison of the Fagerström Test for Cigarette Dependence and Cigarette Dependence Scale in a Treatment-Seeking Sample of Pregnant Smokers.

Introduction: Valid and reliable brief measures of cigarette dependence are essential for research purposes and effective clinical care. Two widely-used brief measures of cigarette dependence are the six-item Fagerström Test for Cigarette Dependence (FTCD) and five-item Cigarette Dependence Scale (CDS-5). Their respective metric characteristics among pregnant smokers have not yet been studied.

Subjective response to nicotine by menstrual phase.

Introduction: The luteal menstrual phase might be a favorable time for smoking cessation when non-nicotine interventions (e.g. counseling, bupropion) are used, whereas the follicular menstrual phase appears favorable when nicotine interventions are used.

Mu Opioid Receptor Binding Correlates with Nicotine Dependence and Reward in Smokers.

The rewarding effects of nicotine are associated with activation of nicotine receptors. However, there is increasing evidence that the endogenous opioid system is involved in nicotine's rewarding effects. We employed PET imaging with [11C]carfentanil to test the hypotheses that acute cigarette smoking increases release of endogenous opioids in the human brain and that smokers have an upregulation of mu opioid receptors (MORs) when compared to nonsmokers.

Validation of the French version of the marijuana craving questionnaire (MCQ) generates a two-factor model.

Background: Craving is a major issue in drug addiction, and a target for drug treatment. The Marijuana Craving Questionnaire-Short Form (MCQ-SF) is a useful tool for assessing cannabis craving in clinical and research settings.

Objective: To validate the French version of the MCQ-SF (FMCQ-SF).

Gender differences in neural-behavioral response to self-observation during a novel fMRI social stress task.

Unlabelled: The neural correlates of response to psychosocial stress and gender differences therein are difficult to model experimentally as this type of stressor is difficult to induce in a brain imaging environment. The Trier Social Stress Test (TSST), a behavioral paradigm that reliably induces moderate levels of stress was thus modified for the MRI environment. To determine the neurobehavioral basis of gender differences in response to observing oneself under social evaluative stress, 26 subjects (14 females) performed the TSST while being videotaped.

Motivations to quit cannabis use in an adult non-treatment sample: are they related to relapse?

Background: The majority of cannabis smokers who quit do so without formal treatment, suggesting that motivations to quit are an important part of cessation process. However, little is known about how motivations relate to successful quitting.

Method: A convenience sample of 385 non-treatment-seeking adult cannabis smokers (58% male, age 16-64years at start of quit attempt) who made a "serious" (self-defined) quit attempt without formal treatment while not in a controlled environment were administered the 176-item Marijuana Quit Questionnaire (MJQQ) to assess their motivations to quit and outcome of the quit attempt.

Predicting smoking relapse with a multidimensional versus a single-item tobacco craving measure.

Background: Research suggests that craving is a predictor of smoking relapse. Craving can be assessed by multiple item or multifactorial scales or by single items. However, no systematic comparisons of their prognostic validity or accuracy have been published.

The acute tobacco withdrawal syndrome among black smokers.

Black smokers have greater difficulty quitting tobacco than White smokers, but the mechanisms underlying between-race differences in smoking cessation are not clear. One possibility is that Black smokers experience greater acute withdrawal than Whites. We investigated whether Black (n = 104) and White smokers (n = 99) differed in abstinence-induced changes in self-report, physiological, and cognitive performance measures.

Dose-response effects of spectrum research cigarettes.

Introduction: Experimental cigarettes are needed to conduct studies examining the effects of varying doses of nicotine content on smoking behavior. The National Institute on Drug Abuse contracted with Research Triangle Institute to make such cigarettes available to researchers. The goal of this study was to determine whether cigarettes that vary in nicotine content produce an expected dose-response effect.

Illicit drug use in heavy smokers with and without schizophrenia.

Objective: The prevalence of cigarette smoking among people with schizophrenia is greater than that of the general population. Because smoking and use of other drugs covary, we examined illicit drug use in current smokers not trying to quit or reduce their tobacco use. We recruited outpatient participants who had a DSM-IV diagnosis of schizophrenia or schizoaffective disorder (schizophrenia, n=70) and a control group who had no Axis I psychiatric disorders (control, n=97).

Nicotine enhances alerting, but not executive, attention in smokers and nonsmokers.

Introduction: Difficulty concentrating is a symptom of nicotine withdrawal that can contribute to relapse in individuals trying to quit smoking. The purpose of this study was to determine the effects of nicotine on executive and alerting attention in smokers and nonsmokers.

Methods: Thirty daily smokers who were not tobacco deprived and 30 nonsmokers participated in the study.

Novel use of a lipid-lowering fibrate medication to prevent nicotine reward and relapse: preclinical findings.

Experimental drugs that activate α-type peroxisome proliferator-activated receptors (PPARα) have recently been shown to reduce the rewarding effects of nicotine in animals, but these drugs have not been approved for human use. The fibrates are a class of PPARα-activating medications that are widely prescribed to improve lipid profiles and prevent cardiovascular disease, but these drugs have not been tested in animal models of nicotine reward. Here, we examine the effects of clofibrate, a representative of the fibrate class, on reward-related behavioral, electrophysiological, and neurochemical effects of nicotine in rats and squirrel monkeys.

Diagnostic criteria for cannabis withdrawal syndrome.

Objective: Cannabis withdrawal occurs in frequent users who quit, but there are no accepted diagnostic criteria for a cannabis withdrawal syndrome (CWS). This study evaluated diagnostic criteria for CWS proposed in DSM-V and two earlier proposals.

Method: A convenience sample of 384 adult, non-treatment-seeking lifetime cannabis smokers provided retrospective self-report data on their "most difficult" quit attempt without formal treatment, which was used in this secondary analysis.