DAT1 and COMT Effects on Delay Discounting and Trait Impulsivity in Male Adolescents with Attention Deficit/Hyperactivity Disorder and Healthy Controls
- 25 August 2010
- journal article
- Published by Springer Science and Business Media LLC in Neuropsychopharmacology
- Vol. 35 (12), 2414-2426
- https://doi.org/10.1038/npp.2010.124
Abstract
Choice impulsivity has been linked to dopamine function and is consistently observed in attention deficit/hyperactivity disorder (ADHD) as a preference for smaller-immediate over larger-delayed rewards using choice-delay paradigms. More sophisticated delay discounting paradigms have yielded inconsistent results. Context and sample characteristics may have contributed to these variations. In this study we examine the effect of type (real vs hypothetical) and magnitude of reward as well as of variation in dopamine genes on choice impulsivity. We selected 36 male adolescents with ADHD-combined subtype (ADHD-CT) and 32 controls (mean age=15.42, SD=2.05) to form four roughly equally sized subgroups on the basis of DAT110/6 haplotype dosage (2 copies and COMTval158met and DRD448bp−VNTR polymorphisms, performed a hypothetical and a real-time discounting task and provided self-ratings of trait impulsivity. The ADHD-CT group discounted rewards more steeply than controls only in the hypothetical task, with delay, but not reward magnitude, influencing choices. They also rated themselves as more impulsive compared with controls. DAT110/6 dosage and the COMTVal158Met genotype predicted trait impulsivity and discounting rates in the hypothetical task, but not in the real-time task. Our results directly link variation in genes putatively influencing dopamine signaling in the prefrontal cortex (COMTVal158Met) and the striatum (DAT110/6) with discounting rates in a hypothetical task (but not a real-time task) and self-ratings of trait impulsivity in ADHD-CT and healthy controls. The lack of magnitude effects in the hypothetical task suggests that discounting in this task may be influenced by different processes in ADHD-CT than in healthy controls.Keywords
This publication has 133 references indexed in Scilit:
- Effects of methylphenidate on discounting of delayed rewards in attention deficit/hyperactivity disorder.Experimental and Clinical Psychopharmacology, 2009
- Impulsivity predicts the escalation of cocaine self-administration in ratsPharmacology Biochemistry and Behavior, 2009
- Evaluating Dopamine Reward Pathway in ADHDJAMA, 2009
- The Neurobiology of Decision: Consensus and ControversyNeuron, 2009
- Why cognitive performance in ADHD may not reveal true potential: Findings from a large population-based sampleJournal of the International Neuropsychological Society, 2009
- Does delay discounting play an etiological role in smoking or is it a consequence of smoking?Drug and Alcohol Dependence, 2009
- Sexually dimorphic effects of four genes (COMT, SLC6A2, MAOA, SLC6A4) in genetic associations of ADHD: A preliminary studyAmerican Journal Of Medical Genetics Part B-Neuropsychiatric Genetics, 2008
- Further Evidence of Dopamine Transporter Dysregulation in ADHD: A Controlled PET Imaging Study Using AltropaneBiological Psychiatry, 2007
- Dissociation in performance of children with ADHD and high-functioning autism on a task of sustained attentionNeuropsychologia, 2007
- Behavioral impulsivity predicts treatment outcome in a smoking cessation program for adolescent smokersDrug and Alcohol Dependence, 2006