Continuous performance test in boys with attention deficit hyperactivity disorder: Methylphenidate dose response and relations with observed behaviors

Used frequently in the assessment of attention deficit hyperactivity disorder (ADHD), continuous performance test (CPTs) still lack sufficient empirical support for such use. Recently developed inattention, impulsivity, and dyscontrol scores incorporate both error speed and error type. Our study of 23 boys with ADHD and 15 comparison boys (6-12 years old), replicated findings that the inattention ad dyscontrol indices, but not the impulsivity index, discriminate the ADHD and non-ADHD groups. The impulsivity index, however, discriminated aggressive from nonaggressive groups among the youngsters with ADHD. The dose response patterns of the CPT error scores to stimulant medication were similar to those for naturalistically observed aggression and noncompliance. As for external validity, the CPT scores were weakly related to dimensional measures of observed aggression, but unrelated noncompliance. Although between-group differences were clear in the group data, the CPT revealed adequate specificity but poor sensitivity in identifying individual boys with ADHD. Results only partially support the ecological validity of the CPT and suggest that CPT error scores function differentially depending on the validation task used; extreme scores may have clinical meaning in assessment of youngsters with ADHD.