How do electronic cigarettes affect cravings to smoke or vape? Parsing the influences of nicotine and expectancies using the balanced-placebo design.

OBJECTIVE: Although electronic cigarettes (e-cigarettes) are frequently initiated for smoking cessation, results from the first two clinical trials testing this suggest that the perceived benefits of vaping may be influenced by non-nicotine factors, including cognitive outcome expectancies. The current study investigated the separate and combined effects of nicotine delivery and outcome expectancies on cravings for cigarettes and e-cigarettes using a balanced-placebo experiment.
METHOD: Drug dosage (contains nicotine or not) was crossed with instructional set (told nicotine or non-nicotine) during ad lib e-cigarette use sessions by 128 current e-cigarette users (52 identifying as current cigarette smokers or "dual users"). It was hypothesized that reduction in craving for both cigarettes and e-cigarettes following e-cigarette administration would be driven primarily by the instructional set manipulation, reflecting the influence of outcome expectancies.
RESULTS: As hypothesized, among dual users, a main effect of instructional set emerged on reductions in craving to smoke cigarettes, with participants who were told that their e-cigarette contained nicotine reporting greater craving reduction (p = .046). With respect to reduced cravings for e-cigarettes, we found an interaction between drug dose and instructional set (p = .02) such that nicotine e-cigarettes reduced cravings more than non-nicotine e-cigarettes only among participants told to expect nicotine.
CONCLUSIONS: Findings suggest that cognitive expectancies contribute to the acute effects of e-cigarettes on craving, which may provide guidance for their potential as smoking cessation aids. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

RCT Entities:   Population Interventions Outcomes