Children with attention deficit/hyperactivity disorder and pervasive developmental disorder: Attention and response inhibition on the kiddie continuous performance test

Continuous Performance Test (CPT) is widely used to assess the attention function and response inhibition in both children and adults. This study attempts to examine the performances of boys with attention deficit/ hyperactivity disorder (AD/HD) and pervasive developmental disorder (PDD) with and without comorbid AD/HD using a CPT. Among the various versions of the CPT available, we used the Kiddie CPT (K-CPT) modified for younger children. The K-CPT was administered to children with AD/HD (n=22), those with PDD (n=19), and typically developing children (n=41) from 7 to 12 years of age. All children were drug free at the time of examination. The performances were examined in 6 measures:total number of omission errors (OE), total number of commission errors (CE), mean hit reaction time (HRT), hit reaction time standard error (HRTSE), perceptual sensitivity (d'), and response style (β). Significantly lower scores in d' and a tendency to more errors in CE were found in the AD/HD group compared with the control group. Significantly lower scores in d' and significantly more errors in CE were also found in the PDD group with AD/HD symptoms compared with the control group. Moreover the AD/HD group showed significantly more errors in OE and higher scores in HRTSE compared with the control group. There were no significant group differences between the PDD group without AD/HD symptoms and the control group on all measures. Less favorable scores in AD/HD suggest inadequate selective attention, sustained attention and/or response inhibition. Results of the PDD group with comorbid AD/HD may reflect a basis of AD/HD impairment. Our findings may provide an understanding of neuropsychological characteristics underlying developmental disorders.