title: Reinforcement enhancing effects of acute nicotine via electronic cigarettes.
abstract: BACKGROUND
  Recent human studies confirm animal research showing that nicotine enhances reinforcement from rewards unrelated to nicotine. These effects of acute nicotine via tobacco smoking may also occur when consumed from non-tobacco products.
  
  
  METHODS
  We assessed acute effects of nicotine via electronic cigarettes ("e-cigarettes") on responding reinforced by music, video, or monetary rewards, or for no reward (control). In a fully within-subjects design, adult dependent smokers (N=28) participated in three similar experimental sessions, each following overnight abstinence (verified by CO≤10ppm). Varying only in e-cigarette condition, sessions involved controlled exposure to a nicotine (labeled "36mg/ml") or placebo ("0″) e-cigarette, or no e-cigarette use. A fourth session involved smoking one's own tobacco cigarette brand after no abstinence, specifically to compare responses under typical nicotine satiation with these acute e-cigarette conditions after abstinence.
  
  
  RESULTS
  Reinforced responding for video reward, but not the other rewards, was greater due to use of the nicotine versus placebo e-cigarette (i.e., nicotine per se), while no differences were found between the placebo e-cigarette and no e-cigarette conditions (i.e., e-cigarette use per se). For nicotine via tobacco smoking, responding compared to the nicotine e-cigarette was similar for video but greater for music, while both video and music reward were enhanced relative to the non-nicotine conditions (placebo and no e-cigarette).
  
  
  CONCLUSIONS
  Acute nicotine from a non-tobacco product has some reinforcement enhancing effects in humans, in a manner partly consistent with nicotine via tobacco smoking and perhaps contributing to the rising popularity of nicotine e-cigarette use.
authors.affiliation: Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA 15213, USA. Electronic address: perkinska@upmc.edu.
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Perkins
authors.affiliation: Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA 15213, USA.
authors.forename: Joshua L
authors.initials: JL
authors.lastname: Karelitz
authors.affiliation: Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA 15213, USA.
authors.forename: Valerie C
authors.initials: VC
authors.lastname: Michael
mesh_terms: D000328:Adult; D066300:Electronic Nicotine Delivery Systems / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D009538:Nicotine / Q000008:administration & dosage* / Q000494:pharmacology*; D012054:Reinforcement, Psychology; D012201:Reward; D012907:Smoking / Q000523:psychology*
chemical_list: D009538:Nicotine
keywords: CReSS; E-cigarettes; Nicotine; Reinforcement enhancement; Sensory reward; Smoking