title: Acute effects of D-amphetamine on progressive-ratio performance maintained by cigarette smoking and money.
abstract: BACKGROUND
  Psychomotor stimulants often increase cigarette smoking, although the mechanisms responsible for that effect remain unclear.
  
  
  OBJECTIVE
  The present study was conducted to extend our investigation of the effects of psychomotor stimulant use on the reinforcing effects of cigarette smoking.
  
  
  METHODS
  A progressive-ratio (PR) schedule was used to examine the acute effects of orally administered D-amphetamine (placebo, 5, 10, 15 mg/70 kg) on the reinforcing effects of smoking (2 puffs/ratio) and money (1.00 US dollar/ratio) in 18 adult smokers.
  
  
  RESULTS
  Among the overall sample of 18 smokers, D-amphetamine produced only a modest, non-significant increase in the amount of responding maintained by smoking (PR break point), but effects varied systematically between subjects. D-Amphetamine increased the smoking break point among ten subjects (responders), while leaving unchanged or decreasing the break point in the remaining eight individuals (non-responders). Responders also were more sensitive than non-responders to d-amphetamine's effects on visual-analog ratings of "high", "good effects", "drowsy", and "slurred speech", but not on other subject ratings (i.e., "bad effects", "jittery", "confused") or on any physiological measures (i.e., heart rate, blood pressure, skin temperature). D-Amphetamine did not significantly alter PR break point maintained by money.
  
  
  CONCLUSIONS
  These results provide further evidence that D-amphetamine can increase the reinforcing effects of cigarette smoking, at least among a subset of smokers.
authors.affiliation: Department of Psychology, University of Vermont, 38 Fletcher Place, Burlington, VT 05401, USA.
authors.forename: Stacey C
authors.initials: SC
authors.lastname: Sigmon
authors.forename: Jennifer W
authors.initials: JW
authors.lastname: Tidey
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Badger
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Higgins
mesh_terms: D000328:Adult; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003913:Dextroamphetamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D011594:Psychometrics; D012201:Reward; D012907:Smoking / Q000523:psychology*
chemical_list: D000697:Central Nervous System Stimulants; D003913:Dextroamphetamine