title: Discounting delayed and probabilistic monetary gains and losses by smokers of cigarettes.
abstract: BACKGROUND
  Nicotine dependence has been associated with impulsivity and discounting delayed/uncertain outcomes.
  
  
  OBJECTIVE
  This study had two main objectives: (1) to examine the relationship between the number of cigarettes consumed per day and the degree to which delayed and uncertain monetary gains and losses are discounted by smokers, and (2) to determine the relationship between the estimated dose of nicotine intake per day and the degree to which four types of discounting occur.
  
  
  METHODS
  Twenty seven habitual smokers and 23 never smokers participated in this experiment. They were required to choose between immediate and delayed monetary rewards (or losses), or between guaranteed and probabilistic rewards (or losses).
  
  
  RESULTS
  The degree to which delayed monetary gains were discounted was significantly and positively correlated with both the number of cigarettes smoked and the estimated dose of nicotine intake per day. Conversely, there was no relationship between smoking and the remaining three types of discounting. Also, mild smokers in our sample did not differ from never smokers in discounting monetary gains or losses.
  
  
  CONCLUSIONS
  In general, our results suggest that both the frequency of nicotine self-administration, as well as the dosage, are positively associated with greater delay discounting of gains. One neuropsychopharmacological explanation for this effect is that chronic nicotine intake may induce neuroadaptation of the neural circuitry involved in reward processing.
authors.affiliation: Department of Behavioral Science, Hokkaido University, N10 W7 Kita-ku, Sapporo, 060-0810, Japan. gwd0701@yahoo.co.jp
authors.forename: Yu
authors.initials: Y
authors.lastname: Ohmura
authors.forename: Taiki
authors.initials: T
authors.lastname: Takahashi
authors.forename: Nozomi
authors.initials: N
authors.lastname: Kitamura
mesh_terms: D000328:Adult; D019540:Area Under Curve; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000209:etiology / Q000523:psychology*; D008297:Male; D011336:Probability; D012189:Retrospective Studies; D012201:Reward; D016540:Smoking Cessation / Q000191:economics / Q000523:psychology*; D012919:Social Behavior; D014029:Tobacco Use Disorder / Q000150:complications / Q000191:economics / Q000523:psychology*