Immediate hedonic response to smoking lapses: relationship to smoking relapse, and effects of nicotine replacement therapy

Vaccination against nicotine: an emerging therapy for tobacco dependence

Tobacco dependence is an addiction characterised by compulsive drug-seeking and drug-taking behavior and intensive craving in the absence of tobacco. Nicotine is the major addictive component of tobacco and acts on the reward system in the brain. Together with strong conditional reinforcements, unaided smoking cessation attempts are notoriously unsuccessful and even the most recently introduced pharmacotherapy, varenicline, only achieves a 23% continuous abstinence rate after 1 year. Vaccination against nicotine represents a promising novel concept for treating nicotine addiction. Antibodies against nicotine inhibit the passage of nicotine to brain and thus inhibit its addiction-reinforcing activities. There are three nicotine vaccines that are in clinical development. The first proof-of-concept study in smoking cessation with the vaccine NicQb (Cytos Biotechnology), a nicotine vaccine based on virus-like particles, demonstrated that continuous abstinence rates can be significantly increased by vaccination; however, as expected from the mode of action, a sufficient antibody level had to be achieved. Antibody level dependence of abstinence was also observed with the nicotine vaccine NicVAX (Nabi Biopharmaceuticals). Vaccination against nicotine has the potential of becoming an important therapy against tobacco dependence.

Translational research in medication development for nicotine dependence

A major obstacle to the development of medications for nicotine dependence is the lack of animal and human laboratory models with sufficient predictive clinical validity to support the translation of knowledge from laboratory studies to clinical research. This Review describes the animal and human laboratory paradigms commonly used to investigate the pathophysiology of nicotine dependence, and proposes how their predictive validity might be determined and improved, thereby enhancing the development of new medications.

Ecological momentary assessment in addiction

Numerous symptoms in psychiatry are subjective (e.g., sadness, anxiety, craving or fatigue), fluctuate and are environment dependent. Accurate measurement of these phenomena requires repeated measures, and ideally needs to be performed in the patient's natural environment rather than in an artificial laboratory environment or a protected hospital environment. The usual paper and pencil questionnaires do not meet these two conditions for reasons of logistics. A recently developed method, ecological momentary assessment (EMA), made it possible to implement these field assessments via ingenious use of various devices (most frequently an electronic diary) coupling an auditory signal with computerized data capture. The subject carries the device with him/her at all times, and data is recorded in vivo in real time. The programming of repeated measures in the form of a Likert scale or pull-down menu is easily achieved. A recall alarm system can help increase compliance. Compared with classical self-report, EMA improves the validity of the assessment of certain symptoms, which are the main evaluation criteria in clinical trials concerning certain pathologies (e.g., craving and treatment of addiction), where measurement was previously liable to bias. This article sets out to present this method, its advantages and disadvantages, and the interest it presents in psychiatry, in particular via three original applications developed by the authors including: measurement of reaction time without the knowledge of the subject in order to test certain cognitive models; use of a graphic solution for the data recorded for functional analysis of disorders; and the use of data collection via mobile phone and text messages, which also enables therapeutic interventions in real time by text messages, personalized on the basis of the situational data collected (e.g., in the case of craving, the associated mood, solitary or group consumption or concomitant occupations).

Genetics of nicotinic acetylcholine receptors: Relevance to nicotine addiction

Human twin studies have suggested that there is a substantial genetic component underlying nicotine dependence, ongoing smoking and ability to quit. Similarly, animal studies have identified a number of genes and gene products that are critical for behaviors related to nicotine addiction. Classical genetic approaches, gene association studies and genetic engineering techniques have been used to identify the gene products involved in nicotine dependence. One class of genes involved in nicotine-related behavior is the family of nicotinic acetylcholine receptors (nAChRs). These receptors are the primary targets for nicotine in the brain. Genetic engineering studies in mice have identified a number of subunits that are critical for the ability of nicotine to activate the reward system in the brain, consisting of the dopaminergic cell bodies in the ventral tegmental area and their terminals in the nucleus accumbens and other portions of the mesolimbic system. In this review we will discuss the various lines of evidence suggesting that nAChRs may be involved in smoking behavior, and will review the human and animal studies that have been performed to date examining the genetic basis for nicotine dependence and smoking.

Confirmatory factor analyses and reliability of the modified cigarette evaluation questionnaire

We examined the validity and reliability of the modified Cigarette Evaluation Questionnaire (mCEQ) that assesses the degree to which subjects experience the reinforcing effects of smoking. Data came from three phase II clinical trials (n=626, n=627, n=312) on varenicline for smoking cessation. Comparative fit indexes and non-normed fit indexes from a confirmatory factor analysis exceeded 0.90. Cronbach's alpha for internal consistency reliability exceeded 0.70 for the Smoking Satisfaction domain and the Psychological Reward domain but was less than 0.70 for the Aversion domain; test-retest reliability generally exceeded 0.70 on the three multi-item domains and two single items. The validity and, in general, the reliability of the postulated multidimensional framework of the mCEQ are confirmed and supported by the analyses of three independent studies, with multi-item domains on Smoking Satisfaction (satisfying, taste good, enjoy smoking), Psychological Reward (calm down, more awake, less irritable, help concentrate, reduce hunger), and Aversion (dizziness, nauseous), as well as the single-item assessment on Enjoyment of Respiratory Tract Sensations and on Craving Reduction.

Natural history of nicotine withdrawal

AIMS

To examine the natural history of nicotine withdrawal and individual differences associated with withdrawal duration and severity.

DESIGN AND SETTING

Prospective study of withdrawal symptoms among smokers who quit for at least 24 hours. Participants used Ecological Momentary Assessment to monitor symptoms in their natural environment using an Electronic Diary (ED).

PARTICIPANTS

A total of 214 cigarette smokers (59% female, 92% Caucasian).

INTERVENTION

All participants received a clinic-based, behavioral, group cessation intervention. Severity and duration of withdrawal was not addressed explicitly in treatment.

MEASUREMENTS

Participants were 'beeped' by the ED approximately five times/day to complete affect assessments (negative affect, arousal, attention disturbance, restlessness), and daily assessments of sleep disturbance (at waking) and of cognitive performance (each evening) for a week prior to quitting and for up to 21 days after quitting. Withdrawal was considered resolved when withdrawal scores returned to baseline levels for at least 2 consecutive days.

FINDINGS

All symptoms returned to baseline levels within 10 days of quitting. All variables except arousal and sleep disturbance showed change over time. No robust predictors of individual differences in withdrawal responses emerged.

CONCLUSIONS

The time-course of withdrawal may be shorter than previously reported. The natural history of nicotine withdrawal may have implications for theories of withdrawal and smoking relapse and for smoking cessation treatment.

Toward a model of drug relapse: an assessment of the validity of the reinstatement procedure

BACKGROUND AND RATIONALE

The reinstatement model is widely used to study relapse to drug addiction. However, the model's validity is open to question.

OBJECTIVE

We assess the reinstatement model in terms of criterion and construct validity.

RESEARCH HIGHLIGHTS AND CONCLUSIONS

We find that the reinstatement model has adequate criterion validity in the broad sense of the term, as evidenced by the fact that reinstatement in laboratory animals is induced by conditions reported to provoke relapse in humans. The model's criterion validity in the narrower sense, as a medication screen, seems promising for relapse to heroin, nicotine, and alcohol. For relapse to cocaine, criterion validity has not yet been established primarily because clinical studies have examined medication's effects on reductions in cocaine intake rather than relapse during abstinence. The model's construct validity faces more substantial challenges and is yet to be established, but we argue that some of the criticisms of the model in this regard may have been overstated.