Relating individual differences in the reinforcing value of smoking and dependence severity to nicotine exposure levels in vulnerable populations.

Cigarette smoking is overrepresented in populations with psychiatric conditions and socioeconomic disadvantage. Greater understanding of the role of reinforcement and nicotine dependence in smoking among vulnerable populations may facilitate development of better targeted interventions to reduce smoking. Prior research demonstrated that individual differences in the reinforcing value of smoking and nicotine-dependence severity predicted total nicotine-exposure in vulnerable populations. The present study uses multivariate regression to address two aims: (1) Quantify the degree to which the reinforcing value of smoking, assessed using the Cigarette Purchase Task (CPT), and dependence severity assessed using the Fagerström Test of Nicotine Dependence and Brief Wisconsin Inventory of Smoking Dependence Motives (B-WISDM) each account for individual differences in cotinine-plus-3'-hydroxycotinine (COT+3HC) levels. (2) Explore whether there is overlap in the variance accounted for by the CTP, FTND, and B-WISDM. Participants were 628 adults with co-morbid psychiatric conditions or socioeconomic disadvantage who smoked daily. The CPT, FTND, and B-WISDM models accounted for 23.76%, 32.45%, and 29.61% of the variance in COT+3HC levels, respectively. Adding CPT to the FTND model failed to increase the variance accounted for and adding it to the B-WISDM model did so by only 1.2% demonstrating considerable overlap in the variance in nicotine exposure levels accounted for by these three instruments. These results provide new knowledge on the relationship between individual differences in the reinforcing value of smoking and nicotine-exposure levels and suggest differences in reinforcing value may underpin a considerable portion of the variance in nicotine exposure accounted for by dependence severity.

Identifying message content to reduce vaping: Results from online message testing trials in young adult tobacco users.

INTRODUCTION: Young adults' e-cigarette use is associated with perceptions that e-cigarettes are less harmful or addictive than cigarettes, socially acceptable, and appealing. This study developed and tested vaping educational messages addressing these factors: 1) Harm Perceptions, 2) Addictiveness, 3) Social Use, and 4) Flavors. METHODS: Two message trials were conducted in U.S. Amazon Mechanical Turk workers aged 18-24 using a 2 (content: addiction, harm) × 3 (theme: alone, + flavors, + social) design with multiple messages in each of the six categories. Participants were assigned to view a random subset of messages and report on likeability and perceived message effectiveness (PME). Phase 1 (n = 200) tested 33 messages and 32 images. Phase 2 (n = 769) tested combinations of Phase 1's 24 most effective messages with 6 images rated most likeable or effective. Linear mixed effects models assessed the effect of content, theme, image, and their interactions on message response. RESULTS: In both trials, most participants were past 30-day tobacco users. Harm content messages produced higher PME ratings than addiction content messages, and flavor theme messages were correlated with higher likeability scores than "content alone" theme messages. In Phase 2, flavor and social message themes decreased the PME of harm messages. There was no effect of images on either outcome controlling for the independent or interaction effects of content, theme, and image. CONCLUSIONS: Messages conveying the harms of vaping may be best for reducing vaping in young adult tobacco users; flavor and social themes may diminish their effectiveness.

Abuse liability of cigarettes with very low nicotine content in pregnant cigarette smokers.

The U.S. Food and Drug Administration has proposed reducing the nicotine content of cigarettes to a minimally-addictive level. To our knowledge, this study is the first to examine how pregnant smokers respond to very low nicotine content (VLNC) cigarettes. In Phase 1, participants blindly sampled two VLNC cigarettes (0.4 and 2.4 mg/g of tobacco) and their usual brand (UB) cigarette in separate sessions, then completed a behavioral economic simulation task and measures of subjective effects, craving/withdrawal, and smoking topography. Phase 2 directly compared the relative reinforcing effects of the cigarettes using concurrent choice testing. All possible dose-pair combinations were tested in separate sessions where puffs were earned ad libitum by clicking the code associated with their preferred cigarette 10 times. Phase 3 tested the 0.4 mg/g-UB dose-pair where UB puffs could be earned with a progressively incremented number of clicks (maximum 8400). Ten pregnant smokers in Burlington, VT and Baltimore, MD participated in 2017-2018. Regarding abuse liability, participants chose the 0.4-mg/g dose less than UB (22% vs. 78%) during concurrent choice testing and the 0.4-mg/g dose sustained less demand than the 2.4-mg/g and UB doses on the simulation task. Positive subjective effects were also lower for both VLNC cigarettes vs. UB. Each cigarette reduced nicotine craving/withdrawal and no significant changes indicative of compensatory smoking were noted. Reducing the nicotine content of cigarettes may decrease their abuse liability in pregnant smokers without causing untoward craving/withdrawal or compensatory smoking. Studies of extended exposure to VLNCs in pregnant women are warranted.