Task demands interact with the single and combined effects of medication and contingencies on children with ADHD

Abstract

Objective: To investigate single and combined effects of stimulant medication and contingencies on the performance of ADHD children with tasks involving different cognitive demands.

Method: Children diagnosed with ADHD participated in a within-subjects design. At two separate sessions, children on either medication or placebo (administered in a double-blind fashion) completed two tasks, a match-to-sample task and a stop-signal task, under three conditions (reward, response cost, and no contingency) in a counterbalanced order.

Results: Contingencies and medication administered singly improved performance on both tasks. For the match-to-sample task, the combination of medication and contingencies was more efficacious than either alone. For the stop-signal task, the combination of medication and reward was no more effective than either alone; however, medication and response cost combined was more effective than either treatment alone.

Conclusion: Results suggest that both medication and contingencies improve task performance. The findings suggest that task demands interact with single and combined treatment effects.