A comparison of the cognitive deficits in reading disability and attention-deficit/hyperactivity disorder

Erik G. Willcutt, Bruce F. Pennington, Richard Boada, Jamie S. Ogline, Rachel A. Tunick, Nomita A. Chhabildas, Richard K. Olson

Research output: Contribution to journalArticle

307 Scopus citations


This study used a nonreferred sample of twins to contrast the performance of individuals with reading disability (RD; n = 93), attention-deficit/hyperactivity disorder (ADHD; n = 52), RD and ADHD (n = 48), and neither RD nor ADHD (n = 121) on measures of phoneme awareness (PA) and executive functioning (EF). Exploratory factor analysis of the EF measures yielded underlying factors of working memory, inhibition, and set shifting. Results revealed that ADHD was associated with inhibition deficits, whereas RD was associated with significant deficits on measures of PA and verbal working memory. The RD + ADHD group was most impaired on virtually all measures: providing evidence against the phenocopy hypothesis as an explanation for comorbidity between RD and ADHD.

Original languageEnglish (US)
Pages (from-to)157-172
Number of pages16
JournalJournal of Abnormal Psychology
Issue number1
StatePublished - Jan 1 2001


ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Biological Psychiatry

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