Investigating late-onset ADHD: a population cohort investigation

Miriam Cooper*, Gemma Hammerton, Stephan Collishaw, Kate Langley, Ajay Thapar, Søren Dalsgaard, Evie Stergiakouli, Kate Tilling, George Davey Smith, Barbara Maughan, Michael O'Donovan, Anita Thapar, Lucy Riglin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

40 Citations (Scopus)

Abstract

Background: Adult ADHD has been assumed to be a continuation of childhood-onset ADHD. However, recent studies have identified individuals with ADHD in adulthood who have not had ADHD in childhood. Whether or not these individuals have a ‘typical’ neurodevelopmental profile is not clear. Methods: We tested two explanations for the emergence of apparent late-onset ADHD symptomatology using the ALSPAC epidemiological cohort, by grouping individuals according to their scores on the Strengths and Difficulties Questionnaire (SDQ) hyperactivity subscale at ages 12 and 17 years. First, we tested whether some of those with apparent late-onset ADHD symptoms had been potentially misclassified on the basis of earlier SDQ hyperactivity scores (ages 7, 8 and 9 years) or of subthreshold symptoms at age 12 years. Second, we investigated the possibility that those with ‘genuine’ late-onset ADHD symptoms had a delayed manifestation of the same liability that underlies childhood-onset symptoms, by investigating whether they had a similar profile of neurodevelopmental impairments (in the domains of autistic symptomatology, language, reading, spelling, executive functioning and IQ) as those with typical childhood-onset ADHD. Results: N = 56/75 (75%) of those with apparent late-onset ADHD had had high ADHD scores at least one point in childhood, suggesting that they may have been misclassified on the basis of their score at age 12 years. The remaining 19 individuals (25%) with genuine late-onset ADHD symptoms did not show a profile of neurodevelopmental impairment typically seen in ADHD, instead showing similar levels of autistic symptoms, language skills, executive functioning ability and IQ to those without ADHD symptoms. The only exceptions were that this group showed reading and spelling problems at age 9 years. Conclusions: Our work suggests that this small number of individuals with genuine late-onset symptoms may not be most appropriately considered as having a typical neurodevelopmental disorder.

Original languageEnglish
Pages (from-to)1105-1113
Number of pages9
JournalJournal of Child Psychology and Psychiatry and Allied Disciplines
Volume59
Issue number10
Early online date23 Apr 2018
DOIs
Publication statusPublished - 1 Oct 2018

Keywords

  • Avon Longitudinal Study of Parents and Children
  • Late-onset ADHD
  • neurodevelopment
  • Strengths and Difficulties Questionnaire

Fingerprint

Dive into the research topics of 'Investigating late-onset ADHD: a population cohort investigation'. Together they form a unique fingerprint.

Cite this