A Novel Abuse Liability Assessment of E-Cigarettes in Young Adults II: Reinforcement Enhancement and Follow-Up Assessment

A double-blind study was performed to test the abuse liability of electronic nicotine delivery systems (ENDS) in young adults; in particular, the influence of nicotine on reward sensitivity was assessed. A total of 53 healthy nonusers participated in experimental sessions during which they played a video game made available on a progressive ratio schedule of reinforcement and self-administered nicotine via ENDS. Participants were randomized into one of three groups. Two groups received either a dedicated concentration of nicotine (6 and 12 mg) or a placebo, and whether they received the placebo or their dedicated nicotine dose was randomly determined on a session-by-session basis to mask the sequencing of drug administration. The third group received only a 0 mg (placebo) vaping device during all sessions. In comparison to all placebo conditions, nicotine-induced reward sensitization was evidenced on behavioral measures of video game reinforcement, but not subjective appraisals of the vaping experience. A 1-month follow-up survey provided evidence that reinforcement enhancement by nicotine predicts increased abuse liability of ENDS. Public Health Significance A portion of nicotine's potential for abuse and dependence may lie in its ability to enhance reinforcers that are experienced in the presence of nicotine. We assessed how electronic nicotine delivery altered the rewarding value of video games in young adult nonusers and also assessed nicotine product use in the months following laboratory exposure to nicotine.