The clinical utility of three visual attention tests to distinguish adults with ADHD from normal controls

Background. Adult patients with ADHD may go unrecognised and undiagnosed. This can result in psychosocial and functional decline. Objectives. To investigate the clinical use of three objective computerised tests in the diagnosis of adult patients with ADHD. Methods. Case-control study. Inclusion criteria: aged 18-65, ADHD diagnosis; exclusion criteria: visual impairments, colour vision deficiencies, acute mental illness, amnesia, and learning difficulties. ADHD was diagnosed with Conners’ Adult ADHD Diagnostic Interview (n=14) and were matched for gender and age against normal controls (n=30). Three computer-based tasks, Stroop test, Stroop Plus, and Perceptual Selectivity test were completed. Accuracy (%) and response time (ms) were measured. Generalized Estimating Equations method was used to analyse those repeated measurements data. The Area Under the Curve (AUC) was calculated for each test. Results. Mean age of cases was 47.29 (SD 9.03), 9 males. Mean age of controls was 41.57 (SD 11.42), 13 males. Individuals with ADHD had significantly worse performances in both accuracy and response time in all the tests. The best discriminate ability was the Stroop test (accuracy and response time), followed by the Perceptual Selectivity test (response time). Comparisons of AUCs of the tests did not show any significant differences. Age had a significant effect on the Stroop and Stroop Plus tests but not in the Perceptual Selectivity test. Conclusions. Adults with ADHD have a longer response time and perform less accurately than controls. Thus, these data suggest that there is a use for objective visual attention tests in the diagnosis of adult ADHD.