The impact of reinforcement contingencies on AD/HD: A review and theoretical appraisal

One of the core deficits in attention deficit/hyperactivity disorder (AD/HD) is thought to be an aberrant sensitivity to reinforcement, such as reward and response cost. Twenty-two studies (N=1181 children) employing AD/HD and reinforcement contingencies are reviewed from vantage points: task performance, motivation, and psychophysiology. Results indicate that reinforcement contingencies have a positive impact on task performance and levels of motivation for both children with AD/HD and normal controls. There is evidence that the effect related to task performance is somewhat more prominent in AD/HD. There is some evidence that a high intensity of reinforcement is highly effective in AD/HD. Children with AD/HD prefer immediate over delayed reward. From a psychophysiological point of view, children with AD/HD seem less sensitive to reinforcement compared to controls. While comorbid disorders are suggested to be confounders of the dependent variables, many studies do not examine the effect of oppositional defiant disorder (ODD) and conduct disorder (CD). We discuss the implications of the findings for five theoretical frameworks, including the model by Haenlein and Caul (1987), Douglas (1999), the cognitive-energetic model (CEM) (Sergeant et al., 1999), the dual-pathway model (Sonuga-Barke, 2003) and the BIS/BAS model (Quay, 1988a, Quay, 1988b and Quay, 1988c). Results show a discrepancy between the theoretical models and the behavioural findings.