Withdrawal Symptoms From E-Cigarette Abstinence Among Adult Never-Smokers: A Pilot Experimental Study

Cannabidiol Reduces Nicotine Withdrawal Severity and State Anxiety During an Acute E-cigarette Abstinence Period: A Novel, Open-Label Study

Introduction: Despite efforts to curb nicotine use, 8.1 million adults in the United States use e-cigarettes. Notably, the majority of nicotine-containing e-cigarette users report wanting to quit in the near future, yet there is a dearth of research surrounding intervention efforts. Cannabidiol (CBD) has potential to facilitate e-cigarette quit attempts by decreasing withdrawal symptom intensity and anxiety during nicotine e-cigarette abstinence. Methods: This study employed an open-label, crossover design (n=20) to test the hypothesis that among daily nicotine-containing e-cigarette users, oral administration of 320 mg CBD would reduce self-reported nicotine withdrawal severity and state anxiety following a 4-h e-cigarette abstinence period compared to withdrawal and anxiety reported after abstinence in the absence of CBD. Results: After controlling for participants' positive CBD expectancies, results were consistent with hypotheses, suggesting CBD reduced both nicotine withdrawal symptom severity and state anxiety during e-cigarette abstinence. Conclusion: These preliminary findings suggest testing the impact of CBD on e-cigarette cessation attempts is warranted.

Effects of short-term nicotine deprivation on delay discounting among young, experienced, exclusive ENDS users: An initial study

Delay discounting describes how rapidly delayed rewards lose value as a function of delay and serves as one measure of impulsive decision-making. Nicotine deprivation among combustible cigarette smokers can increase delay discounting. We aimed to explore changes in discounting following nicotine deprivation among electronic nicotine delivery systems (ENDS) users. Thirty young adults (aged 18-24 years) that exclusively used ENDS participated in two laboratory sessions: one with vaping as usual and another after 16 hr of nicotine deprivation (biochemically assessed). At each session, participants completed a craving measure and three hypothetical delay discounting tasks presenting choices between small, immediate rewards and large, delayed ones (money-money; e-liquid-e-liquid; e-liquid-money). Craving for ENDS significantly increased during short-term nicotine deprivation relative to normal vaping. Delay discounting rates in the e-liquid now versus money later task increased (indicating a shift in preference for smaller, immediate rewards) following short-term nicotine deprivation relative to vaping as usual, but no changes were observed in the other two discounting tasks. Short-term nicotine deprivation increased the preference for smaller amounts of e-liquid delivered immediately over larger, monetary awards available after a delay in this first study of its kind. As similar preference shifts for drug now versus money later have been shown to be indicative of increased desire to use drug as well as relapse risk, the findings support the utility of the current model as a platform to explore interventions that can mitigate these preference shifts. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Reinforcement enhancement by nicotine: A novel abuse-liability assessment of e-cigarettes in young adults

Nicotine can act as a primary positive reinforcer, and as negative reinforcer to relieve withdrawal; we tested whether it can also enhance the reinforcing efficacy of non-drug reinforcers. Young-adult never-users were delivered nicotine via e-cigarette, and a videogame reinforcer was used to test nicotine enhancement. Three dose groups were tested (placebo-only, 6 or 12-mg nicotine), and participants returned to the lab for several sessions over the course of 1 month. Those in the two nicotine-dose groups received placebo on some occasions and nicotine on others; nicotine enhancement of the videogame reinforcer was assessed in a within-subjects fashion by comparing each of the two nicotine groups' dedicated nicotine dose to placebo. In the placebo-only group, progressive-ratio (PR) schedule breakpoints did not alter as a function of videogame exposure, suggesting that the videogame retained its basic-reinforcing properties throughout the study. For the two groups that received nicotine, both doses of nicotine increased PR-schedule breakpoints for the videogame reinforcer relative to the placebo condition. Although nicotine was associated with greater subjective evaluation of the enjoyment of the videogame, it was unrelated to the enjoyment of the e-cigarette device. No evidence was found that nicotine elevated either anhedonia or withdrawal symptoms in the timeframe of the study. The results provide initial evidence that nicotine enhancement, via electronic cigarettes, occurs in non-frequent users of nicotine products and may be a reason they can develop nicotine dependence in the absence of withdrawal and direct effects of nicotine. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Attentional Bias in Non-Smoking Electronic Cigarette Users: An Eye-Tracking Study

INTRODUCTION

This study examined attentional bias (AB) to e-cigarette cues among a sample of non-smoking daily e-cigarette users (n = 27), non-smoking occasional e-cigarette users (n = 32), and control participants (n = 61) who did not smoke or use e-cigarettes. The possibility that e-cigarette users develop a transference of cues to traditional cigarettes was also examined.

METHODS

AB was assessed using a free-viewing eye-gaze tracking methodology, in which participants viewed 180 pairs of images for 4 seconds (e-cigarette and neutral image, e-cigarette and smoking image, smoking and neutral image).

RESULTS

Daily and occasional e-cigarette users attended to pairs of e-cigarette and neutral images equally, whereas non-users attended to neutral images significantly more than e-cigarette images. All three groups attended to e-cigarette images significantly more than smoking images, with significantly larger biases for e-cigarette users. There were no between-group differences in attention to pairs of smoking and neutral images. A moderation analysis indicated that for occasional users but not daily users, years of vaping reduced the bias toward neutral images over smoking images.

CONCLUSIONS

Taken together, the results indicate that e-cigarette users exhibit heighted attention to e-cigarettes relative to non-users, which may have implications as to how they react to e-cigarette cues in real-world settings. AB for e-cigarettes did not transfer to traditional cigarette cues, which indicates that further research is required to identify the mechanisms involved in the migration of e-cigarettes to traditional cigarettes.

IMPLICATIONS

This study is the first attempt to examine attentional biases for e-cigarette cues among non-smoking current e-cigarette users using eye-gaze tracking. The results contribute to the growing literature on the correlates of problematic e-cigarette use and indicate that daily and occasional e-cigarette use is associated with attentional biases for e-cigarettes. The existence of attentional biases in e-cigarette users may help to explain the high rate of failure to quit e-cigarettes and provides support for the utility of attentional bias modification in the treatment of problematic e-cigarette use.

Changes in dependence, withdrawal, and craving among adult smokers who switch to nicotine salt pod-based e-cigarettes

BACKGROUND AND AIMS

For electronic cigarettes (e-cigarettes) to be a viable substitute for combustible cigarettes, it is likely that they must be rewarding enough for regular use, indicated by factors such as craving and dependence, important aspects of reinforcement. This study aimed to understand short-term changes in measures of nicotine dependence between groups differing by use trajectory in a switching trial, and within group changes of these measures.

DESIGN

Secondary data analysis of one arm of an e-cigarette randomized clinical trial.

SETTING

San Diego, California and Kansas City, Missouri, United States.

PARTICIPANTS

114 African American (n = 60) and Latinx (n = 54) smokers (58.8% male) attempting to switch to nicotine salt pod system (NSPS) e-cigarettes in a 6-week trial.

MEASUREMENTS

At week 6, participants were classified by use trajectory: exclusive smokers (n = 16), exclusive e-cigarette (n = 32), or dual users (n = 66). E-cigarette, cigarette, and total nicotine dependence (cigarette + e-cigarette), use patterns, cigarette craving and nicotine withdrawal, and cotinine were assessed at baseline and week 6 using standard measures.

FINDINGS

In between group comparisons, exclusive e-cigarette and dual users showed greater reductions in cigarette dependence (e-cigarette: -32.38, 95% CI = -37.7,-27.1; dual: -18.48, 95% CI = -22.2,-14.7), withdrawal (e-cigarette: -6.25, 95% CI = -8.52,-3.98; dual: -3.18, 95% CI = -5.02,-1.34), craving (e-cigarette: -11.44, 95% CI = -14.2,8.7; dual: -9.59, 95% CI = -11.6,-7.59), and cigarettes per day (CPD; e-cigarette: -11.19, 95% CI = -13.1,-9.27; dual: -9.39, 95% CI = -11.3, -7.52) compared with exclusive smokers. In within group analyses, e-cigarette and dual users showed reductions in craving and withdrawal from baseline to week 6. Exclusive e-cigarette and dual users, maintained cotinine levels (all Ps > 0.05) and showed reductions in CPD and cigarette dependence (all Ps < 0.01). Findings were inconclusive regarding changes in total nicotine dependence from baseline to week 6 among exclusive e-cigarette users (P = 0.123). Dual users showed increased total nicotine dependence (P < 0.001) and smokers showed decreased total dependence (P = 0.004).

CONCLUSIONS

Smokers who switch to nicotine salt pod system e-cigarettes maintain their nicotine levels and transfer their dependence, suggesting that nicotine salt pod system e-cigarettes have a similar reinforcement potential to cigarettes and facilitate switching.

Preliminary evaluation of short-term abstinence effects among never-smoking experienced users of modern electronic cigarettes

INTRODUCTION

ECIG use has increased among non-smokers, with the potential negative consequence of developing nicotine dependence. ECIG users report withdrawal symptoms upon abstinence, though the significance of these symptoms has been questioned. This preliminary study aimed to characterize the early timecourse of ECIG withdrawal under forced abstinence.

METHODS

Fifteen never-smoking ECIG users completed two conditions whereby participants either abstained from ECIG use (abstinence) or used their own ECIG (ad lib) for 3 hours. Puff topography in this latter condition was measured via video observation. Outcome measures included heart rate, subjective ratings of withdrawal, cognitive performance, and choice behavior.

RESULTS

Heart rate was lower during abstinence compared to ad lib use (F=12.60, p<.01, ƞp  2=0.47). Higher levels of craving (F=4.98, p<.05, ƞp  2=0.26) and lower levels of nicotine effects (e.g., dizzy, F=4.62, p<.05, ƞp  2=0.36) were reported during abstinence compared to ad lib use. Interaction effects were observed for both factors of the Questionnaire of Smoking Urges: Brief (Fs>3.56, ps<.05, ƞp  2s=0.21-0.27), with factor scores increasing from baseline to 90 minutes in the abstinent condition only. Inhibitory control was impaired at 120 min in the abstinent condition only (F=7.51, p<.05, ƞp  2=0.50).

CONCLUSIONS

Never-smoking ECIG users experienced aversive withdrawal symptoms within 2-3 hours of abstinence. Future work should include other control conditions, such as placebo ECIGs or nicotine replacement therapy, and biomarkers of nicotine exposure, as well as examine withdrawal as a function of device type.

IMPLICATIONS

Never-smoking ECIG users experience some aversive nicotine withdrawal symptoms within two to three hours of abstinence. Relative to ad lib ECIG use, abstinence decreased heart rate and inhibitory control, as well as increased subjective ratings of withdrawal such as craving and intention to vape. Those same symptoms might be suppressed by self-administration of ECIGs. Experiencing withdrawal upon abstinence may indicate that ECIGs can cause dependence without a history of other tobacco use.

Unique, long-term effects of nicotine on adolescent brain

Adolescence is a time of major plasticity of brain systems that regulate motivated behavior and cognition, and is also the age of peak onset of nicotine use. Although there has been a decline in teen use of cigarettes in recent years, there has been a huge increase in nicotine vaping. It is therefore critically important to understand the impact of nicotine on this critical phase of brain development. Animal studies have shown that nicotine has unique effects on adolescent brain. The goal of this review is therefore to systematically evaluate age- and sex-differences in the effects of nicotine on brain and behavior. Both acute and chronic effects of nicotine on brain biochemistry and behavior, particularly drug reward, aversion, cognition and emotion, are evaluated. Gaps in our current knowledge that need to be addressed are also highlighted. This review compares and integrates human and animals findings. Although there can be no experimental studies in humans to confirm similar behavioral effects of teen nicotine exposure, an emerging observational literature suggests similarities across species. Given the substantial evidence for long-term negative impact of adolescent nicotine exposure on brain and behavior, further longitudinal assessment of health outcomes in teen and young adult e-cigarette users is warranted.