Neurocognitive markers of late-onset ADHD: a 6-year longitudinal study

Shahrzad Ilbegi*, Jan K. Buitelaar, Pieter J. Hoekstra, Catharina A. Hartman, Barbara Franke, Stephen V. Faraone, Jaap Oosterlaan, Marjolein Luman, Marloes van Lieshout, Nanda N.J. Rommelse

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Background: There is an increased interest in ‘late-onset’ attention-deficit/hyperactivity disorder (ADHD), referring to the onset of clinically significant ADHD symptoms after the age of 12 years. This study aimed to examine whether unaffected siblings with late-onset ADHD could be differentiated from stable unaffected siblings by their neurocognitive functioning in childhood. Methods: We report findings from a 6-year prospective, longitudinal study of the Dutch part of the International Multicenter ADHD Genetics (IMAGE) study, including individuals with childhood-onset (persistent) ADHD (n = 193), their siblings with late-onset ADHD (n = 34), their stable unaffected siblings (n = 111) and healthy controls (n = 186). At study entry (mean age: 11.3) and follow-up (mean age: 17.01), participants were assessed for ADHD by structured psychiatric interviews and multi-informant questionnaires. Several neurocognitive functions were assessed at baseline and after 6 years, including time reproduction, timing variability (reaction time variability and time production variability), reaction time speed, motor control and working memory; intelligence was taken as a measure of overall neurocognitive functioning. Results: Siblings with late-onset ADHD were similar to individuals with childhood-onset ADHD in showing longer reaction times and/or higher error rates on all neurocognitive measures at baseline and follow-up, when compared to healthy controls. They differed from stable unaffected siblings (who were similar to healthy controls) by greater reaction time variability and timing production variability at baseline. No significant group by time interaction was found for any of the tasks. Conclusions: For unaffected siblings of individuals with ADHD, reaction time variability and timing production variability may serve as neurocognitive marker for late-onset ADHD.

Original languageEnglish
Pages (from-to)244-252
Number of pages9
JournalJournal of Child Psychology and Psychiatry and Allied Disciplines
Issue number2
Publication statusPublished - Feb 2021

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