The Abuse Potential and Appeal of Electronic Cigarettes for Adult Cigarette Smokers

Abstract

Electronic cigarettes (e-cigarettes) have been considered by some public health scientists and by cigarette smokers as a reduced-harm alternative to cigarettes. While switching completely from cigarettes to e-cigarettes is associated with lower levels of tobacco-related toxicants, most of these smokers continue using their cigarettes as dual users. It would be important, therefore, to understand whether and which e-cigarette product characteristics lead to complete switching. The purpose of the current dissertation was to evaluate and compare the abuse potential of e-cigarettes with different product characteristics, as higher abuse potential and appeal are associated with higher uptake and use of a product. Chapter 1 provided a systematic review of 104 studies conducted between 2007 and 2020 on the impacts of e-liquid nicotine concentration and flavor on abuse potential and appeal of e-cigarettes for adult current and former cigarette and e-cigarette users. Chapters 2 and 3 used a secondary analysis of a multi-site 8-week clinical trial of smokers who were not seeking smoking cessation treatment but who were instructed to switch completely to e-cigarettes (Vuse Solo) to determine whether initial subjective responses to e-cigarettes (Chapter 2) and behavioral economic demand of cigarettes and e-cigarettes (Chapter 3) related to the successful substitution of e-cigarettes for cigarettes and the extent of cigarette and e-cigarette use. Chapter 4 utilized these measures to assess the abuse potential and appeal of a nicotine salt pod e-cigarette (Juul) with different e-liquid nicotine concentrations (3% and 5%) and flavors (Virginia Tobacco and Menthol) for adult cigarette smokers. Results from Chapter 1 suggest that higher nicotine concentration and access to a variety of flavors are likely associated with higher abuse potential and appeal of e-cigarettes for adult current and former cigarette and e-cigarette users. Chapter 2 concluded that higher initial subjective responses were related to lower cigarette and higher e-cigarette use 6-8 weeks later, supporting the conclusion from Chapter 1 that higher abuse potential is related to higher uptake and switching behavior. Chapter 3 found that e-cigarette demand was related to future e-cigarette use, but cigarette demand better predicted both e-cigarette use and switching behavior, suggesting either a need to increase the reinforcing efficacy of e-cigarettes or decrease the reinforcing efficacy of cigarettes to increase complete switching. Chapter 4 did not detect differences due to nicotine and/or flavor with regards to subjective responses or behavioral economic demand but did find that these devices reliably decreased withdrawal and cigarette smoking urges, and that menthol smokers overwhelmingly chose menthol over tobacco flavor. Overall, these studies add to the current literature on e-cigarette abuse potential and appeal and add to the discussion surrounding e-cigarette regulation and e-cigarettes as a potential smoking cessation aid.