Inattentive and impulsive profiles of the CPT-II and their relationship with DSM-IV ADHD subtypes

The DSM-IV recognizes three subtypes of ADHD based on the results of field trials and factor analytic studies that identified two dimensions of symptoms in the disorder: inattention and hyperactivity/impulsivity. The three DSM-IV subtypes are predominantly inattentive (ADHD/I), predominantly hyperactive-impulsive (ADHD/HI), and combined type (ADHD/C).; Study of these three ADHD subtypes has suggested differences in demographics, prevalence, course, rates of comorbid conditions, possible etiology, and treatment response. Given the potential clinical meaningfulness of identifying these subtypes, ADHD assessment instruments that discriminate between subtypes are needed.; The CPT-II is a version of the continuous performance task designed to measure symptoms of inattention and impulsivity. Conners' (2000) suggests that the pattern of elevated scores on the CPT-II can be used to determine whether a child's problem is primarily one of inattention or impulsivity. The present study examines whether the profiles generated by the CPT-II are clinically meaningful by comparing the performance of a clinical sample of children (N = 40) with different profile types on measures of attention, impulsivity, depression, anxiety, learning problems, and executive function.; It was hypothesized that (1) the children with clinical CPT-II profiles would exhibit greater impairment on the other measures than the children with nonclinical profiles, (2) the inattentive and impulsive CPT-II groups would differ in ways consistent with the literature on the differences between the ADHD subtypes, and (3) that omission and commission scores on the CPT-II would be useful for identifying groups of children who would differ in ways consistent with the differences reported between the ADHD subtypes.; The results did not support Hypothesis 1; the children with clinical and nonclinical CPT-II profiles did not differ significantly on the dependent measures. For Hypothesis 2, the children with inattentive, impulsive, and indeterminate CPT-II profiles differed significantly only in their use of semantic clustering during a list-learning task. There was also a nonsignificant trend for differences in self-reported anxiety between the three CPT-II profile groups. The results failed to support Hypothesis 3 and did not identify differences between children with differing levels of omission and commission scores.; The clinical implications and suggestions for future research are discussed.