Abstract
In humans and animals, future rewards are devalued as a function of delay. This phenomenon is referred to as delay discounting. A higher discounting rate predicts impulsive choice behavior such as a preference for small, immediate rewards. Using a delay discounting questionnaire for children, the present study examined delay discounting of monetary rewards in children with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) to evaluate their impulsivity. A questionnaire about self-regulating behavior in daily life was also used to validate the discounting rate. Children that chose small, immediate rewards in the questionnaire about self-regulating behavior showed higher discounting rates than did children who chose larger, delayed rewards, suggesting that discounting rates are correlated with impulsive choice behavior in daily life. Children with ADHD and ASD did not differ significantly in discounting rates; however, both groups showed higher rates than did previously reported typically developing children, implying that children with ADHD and ASD tend to devalue future rewards more steeply. Discounting rates in children with ADHD, but not those with ASD, were negatively correlated with age. These results suggest that delay discounting may be useful for understanding and assessing impulsivity in children with ADHD and ASD.
