Are changes in ADHD course reflected in differences in IQ and executive functioning from childhood to young adulthood?

Journal Article (Journal Article)

Background

Attention-deficit hyperactivity disorder (ADHD) is associated with poorer cognitive functioning. We used a developmental, genetically-sensitive approach to examine intelligence quotient (IQ) from early childhood to young adulthood among those with different ADHD courses to investigate whether changes in ADHD were reflected in differences in IQ. We also examined executive functioning in childhood and young adulthood among different ADHD courses.

Methods

Study participants were part of the Environmental Risk (E-Risk) Longitudinal Twin Study, a population-based birth cohort of 2232 twins. We assessed ADHD in childhood (ages 5, 7, 10 and 12) and young adulthood (age 18). We examined ADHD course as reflected by remission, persistence and late-onset. IQ was evaluated at ages 5, 12 and 18, and executive functioning at ages 5 and 18.

Results

ADHD groups showed deficits in IQ across development compared to controls; those with persistent ADHD showed the greatest deficit, followed by remitted and late-onset. ADHD groups did not differ from controls in developmental trajectory of IQ, suggesting changes in ADHD were not reflected in IQ. All ADHD groups performed more poorly on executive functioning tasks at ages 5 and 18; persisters and remitters differed only on an inhibitory control task at age 18.

Conclusions

Differences in ADHD course - persistence, remission and late-onset - were not directly reflected in changes in IQ. Instead, having ADHD at any point across development was associated with lower average IQ and poorer executive functioning. Our finding that individuals with persistent ADHD have poorer response inhibition than those who remitted requires replication.

Full Text

Duke Authors

Cited Authors

  • Agnew-Blais, JC; Polanczyk, GV; Danese, A; Wertz, J; Moffitt, TE; Arseneault, L

Published Date

  • December 2020

Published In

Volume / Issue

  • 50 / 16

Start / End Page

  • 2799 - 2808

PubMed ID

  • 31718730

Electronic International Standard Serial Number (EISSN)

  • 1469-8978

International Standard Serial Number (ISSN)

  • 0033-2917

Digital Object Identifier (DOI)

  • 10.1017/s0033291719003015

Language

  • eng