Sustained attention and response inhibition in young children at risk for Attention Deficit/Hyperactivity Disorder

Background: Studies of school-aged children, adolescents, and adults with Attention Deficit/Hyperactivity Disorder (ADHD) have variably shown ADHD-related impairment in both inhibitory control and sustained attention. However, few studies have examined ADHD-associated patterns of performance on these tasks among younger children (below age 7 years). Methods: A combined continuous performance test and go/no-go task (CPT/GNG) and the Day-Night Stroop Task (DNST) were administered to an ethnically diverse sample of 3.44- to 6.95-year-old children rated by parents and teachers as being either high risk or low risk for ADHD. All children performed the DNST (N = 71) and a subset of the sample (N = 44) performed the CPT/GNG. Analyses assessed task validity as well as the effects of age and risk status. Results: Significant main effects for age and risk status were found on all tasks. In addition, age x condition interactions were found for the CPT and DNST, which suggest that the tasks were sensitive to age-related changes in sustained attention and inhibitory control respectively. No significant risk status x condition interactions were found, suggesting that young children at risk for ADHD do not exhibit specific deficits in either inhibitory control or sustained attention. The most consistent effect related to risk status across tasks was the greater number of errors and longer and more variable reaction times on the part of children at risk for ADHD irrespective of condition. Conclusions: ADHD-associated decrements in performance on these tasks appear to be attributable either to generalized behavioral dysregulation or poor state regulation rather than to deficient inhibitory control.