Aim: The objective of this study was to investigate which attentional components are of predictive utility in differentiating children with attention-deficit-hyperactivity disorder, combined type (ADHD-C) from their peers without ADHD.
Methods: Thirty-four children participated in the study: 17 males with ADHD-C (mean age 10y 4mo, SD 1y 9mo) and 17 comparison children (12 males, 5 females; mean age 10y 8mo, SD 1.7y). Attentional functions were assessed using a computer-administered, child-friendly test series in German (i.e. Testbatterie zur Aufmerksamkeitsprüfung für Kinder; KITAP). The KITAP measures several attentional components, including alertness and executive attention (inhibition, divided attention, flexibility).
Results: The variable best able to discriminate between children with and without ADHD-C was found to be response time variability in a go/no go task, followed by, in order, number of errors in a divided attention task and response time variability in an alertness task. However, group discrimination was not facilitated by differences in either response latency or accuracy of response in visuospatial attention and attentional flexibility tasks.
Interpretation: The assessment of attentional functions proved to be a powerful instrument for discriminating between children with and without ADHD-C. Notably, the discriminative power of executive attention was found to be task dependent and dependent on processing demands.