title: The faster internal clock in ADHD is related to lower processing speed: WISC-IV profile analyses and time estimation tasks facilitate the distinction between real ADHD and pseudo-ADHD.
abstract: Alterations in temporal processing may represent a primary cause of key symptoms in ADHD. This study is aimed at investigating the nature of time-processing alterations in ADHD and assessing the possible utility of testing time estimation for clinical diagnostics. Retrospective verbal time estimation in the range of several minutes was examined in 50 boys with ADHD and 53 boys with other mental disorders. All participants (age 7-16) attended an outpatient clinic for ADHD diagnostics. The diagnostic assessment included the WISC-IV. Subjects with ADHD made longer and less accurate duration estimates than the clinical control group. The ADHD group showed a specific WISC-IV profile with processing speed deficits. In the ADHD group there was a correlation between processing speed and quality of time estimation that was not observed in the comparison group: higher processing speed indices were related to more accurate duration estimates. The findings provide support for the presence of a faster internal clock in subjects with ADHD and lend further support to the existence of a specific WISC-IV profile in subjects with ADHD. The results show that analyzing WISC-IV profiles and time estimation tasks are useful differential diagnosis tools, particularly when it comes to distinguishing between "real ADHD" and pseudo-ADHD.
authors.affiliation: SANA-Klinikum, Zentrum für seelische Gesundheit des Kindes- und Jugendalters, Remscheid, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Walg
authors.affiliation: SANA-Klinikum, Zentrum für seelische Gesundheit des Kindes- und Jugendalters, Remscheid, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Hapfelmeier
authors.affiliation: Heinrich-Heine-University, Düsseldorf, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: El-Wahsch
authors.affiliation: Faculty of Society and Economics, Rhine-Waal University of Applied Sciences, Kleve, Germany. Helmut.Prior@hsrw.eu.|Institute of Psychology, Goethe University, Frankfurt am Main, Germany. Helmut.Prior@hsrw.eu.
authors.forename: Helmut
authors.identifier: http://orcid.org/0000-0002-5108-5839
authors.initials: H
authors.lastname: Prior
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D013998:Time Perception / Q000502:physiology*; D014888:Wechsler Scales / Q000706:statistics & numerical data*
keywords: ADHD; Processing speed; Retrospective time estimation; Time processing; WISC-IV profile