Effects of methylphenidate on discounting of delayed rewards in attention deficit/hyperactivity disorder.
Impulsivity is a central component of attention deficit/hyperactivity disorder (ADHD). Delay discounting, or a preference for smaller, immediate rewards over larger, delayed rewards, is considered an important aspect of impulsivity, and delay-related impulsivity has been emphasized in etiological models of ADHD. In this study, we examined whether stimulant medication, an effective treatment for ADHD, reduced discounting of delayed experiential and hypothetical rewards among 49 children (ages 9-12 years) with ADHD. After a practice day, participants completed a 3-day double-blind placebo-controlled acute medication assessment. Active doses were long-acting methylphenidate (Concerta), with the nearest equivalents of 0.3 and 0.6 mg/kg TID immediate-release methylphenidate. On each testing day, participants completed experiential (real-world money in real time) and hypothetical discounting tasks. Relative to placebo, methylphenidate reduced discounting of delayed experiential rewards but not hypothetical rewards. Broadly consistent with etiological models that emphasize delay-related impulsivity among children with ADHD, these findings provide initial evidence that stimulant medication reduces delay discounting among those with the disorder. The results also draw attention to task parameters that may influence the sensitivity of various delay discounting measures to medication effects.
Department of Psychology.
Keri
K
Shiels
Department of Psychology.
Larry W
LW
Hawk
Department of Pediatrics.
Brady
B
Reynolds
Department of Psychology.
Rebecca J
RJ
Mazzullo
Department of Psychology.
Jessica D
JD
Rhodes
Department of Psychology.
William E
WE
Pelham
Department of Psychology.
James G
JG
Waxmonsky
Department of Psychology.
Brian P
BP
Gangloff
D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000503:physiopathology / Q000523:psychology; D000697:Central Nervous System Stimulants; D002648:Child; D002755:Choice Behavior / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D016503:Drug Delivery Systems / Q000379:methods; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology / Q000627:therapeutic use*; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011930:Reaction Time / Q000187:drug effects; D012055:Reinforcement Schedule; D012201:Reward; D016896:Treatment Outcome
D000697:Central Nervous System Stimulants; D008774:Methylphenidate