Sex Differences in ADHD Symptom Severity

Authors

Anne B. Arnett, University of Denver
Bruce F. Pennington, University of Denver
Erik G. Willcutt, University of Colorado at Boulder
John C. DeFries, University of Colorado at Boulder
Richard K. Olson, University of Colorado at Boulder

Publication Date

10-4-2014

Document Type

Article

Organizational Units

College of Arts Humanities and Social Sciences, Psychology

Keywords

ADHD, Gender difference, Neuropsychology, Cognitive development, Mediation

Abstract

Background

Males show higher rates of attention deficit hyperactivity disorder (ADHD) than do females. Potential explanations include genuine etiological differences or artifact.

Methods

2,332 twin and sibling youth participated in behavioral and cognitive testing. Partially competing models of symptom severity distribution differences, the mean difference, and variance difference models, were tested within a randomly selected subsample. The Delta method was used to test for mediation of sex differences in ADHD symptom severity by processing speed, inhibition and working memory.

Results

The combined mean difference and variance difference models fully explained the sex difference in ADHD symptom severity. Cognitive endophenotypes mediated 14% of the sex difference effect.

Conclusions

The sex difference in ADHD symptom severity is valid and may be due to differing genetic and cognitive liabilities between the sexes.

Publication Statement

Copyright held by author or publisher. User is responsible for all copyright compliance.

Recommended Citation

Arnett, A. B., Pennington, B. F., Willcutt, E. G., DeFries, J. C., & Olson, R. K. (2015). Sex differences in ADHD symptom severity. Journal of Child Psychology and Psychiatry, 56(6), 632-639. DOI:10.1111/jcpp.12337.