Characterizing the ASD-ADHD phenotype: measurement structure and invariance in a clinical sample

Aneta D Krakowski; Katherine Tombeau Cost; Peter Szatmari; Evdokia Anagnostou; Jennifer Crosbie; Russell Schachar; Eric Duku; Stelios Georgiades; Muhammad Ayub; Elizabeth Kelley; Rob Nicolson; Eleanor Pullenayegum; Carolina Barnett-Tapia

doi:10.1111/jcpp.13609

Characterizing the ASD-ADHD phenotype: measurement structure and invariance in a clinical sample

J Child Psychol Psychiatry. 2022 Dec;63(12):1534-1543. doi: 10.1111/jcpp.13609. Epub 2022 Mar 27.

Authors

Aneta D Krakowski¹, Katherine Tombeau Cost², Peter Szatmari^{1

2

3}, Evdokia Anagnostou^{4

5}, Jennifer Crosbie^{1

2}, Russell Schachar^{1

2}, Eric Duku^{6

7}, Stelios Georgiades^{6

7}, Muhammad Ayub⁸, Elizabeth Kelley^{9

10}, Rob Nicolson¹¹, Eleanor Pullenayegum^{12

13}, Carolina Barnett-Tapia^{14

15}

Affiliations

¹ Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
² Department of Psychiatry, Hospital for Sick Children, Toronto, ON, Canada.
³ Centre for Addiction and Mental Health, Toronto, ON, Canada.
⁴ Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, ON, Canada.
⁵ Department of Pediatrics, University of Toronto, Toronto, ON, Canada.
⁶ Department of Psychiatry & Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada.
⁷ Offord Centre for Child Studies, McMaster Children's Hospital and McMaster University, Hamilton, ON, Canada.
⁸ Department of Psychiatry, Queen's University, Kingston, ON, Canada.
⁹ Department of Psychology, Queen's University, Kingston, ON, Canada.
¹⁰ Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada.
¹¹ Department of Psychiatry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
¹² Child Health Evaluative Sciences, Hospital for Sick Children, Toronto, ON, Canada.
¹³ Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
¹⁴ Division of Neurology, Department of Medicine, University Health Network and University of Toronto, Toronto, ON, Canada.
¹⁵ Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada.

PMID: 35342939
DOI: 10.1111/jcpp.13609

Abstract

Background: Autism Spectrum Disorder (ASD) and Attention Deficit Hyperactivity Disorder (ADHD) have considerable overlap, supporting the need for a dimensional framework that examines neurodevelopmental domains which cross traditional diagnostic boundaries. In the following study, we use factor analysis to deconstruct the ASD-ADHD phenotype into its underlying phenotypic domains and test for measurement invariance across adaptive functioning, age, gender and ASD/ADHD clinical diagnoses.

Methods: Participants included children and youth (aged 3-20 years) with a clinical diagnosis of ASD (n = 727) or ADHD (n = 770) for a total of 1,497 participants. Parents of these children completed the Social Communication Questionnaire (SCQ), a measure of autism symptoms, and the Strengths and Weaknesses of ADHD and Normal Behaviour (SWAN) questionnaire, a measure of ADHD symptoms. An exploratory factor analysis (EFA) was performed on combined SCQ and SWAN items. This was followed by a confirmatory factor analysis (CFA) and tests of measurement invariance.

Results: EFA revealed a four-factor solution (inattention, hyperactivity/impulsivity, social-communication, and restricted, repetitive, behaviours and interests (RRBI)) and a CFA confirmed good model fit. This solution also showed good model fit across subgroups of interest.

Conclusions: Our study shows that a combined ASD-ADHD phenotype is characterized by two latent ASD domains (social communication and RRBIs) and two latent ADHD domains (inattention and hyperactivity/impulsivity). We established measurement invariance of the derived measurement model across adaptive functioning, age, gender and ASD/ADHD diagnoses.

Keywords: ADHD; ASD; factor analysis; measurement invariance; measurement structure.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Attention Deficit Disorder with Hyperactivity* / diagnosis
Attention Deficit Disorder with Hyperactivity* / genetics
Autism Spectrum Disorder* / diagnosis
Humans
Parents
Phenotype
Surveys and Questionnaires