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Cited by 231Developmental and Educational NeuropsychologyAttention Deficit Hyperactivity DisorderAutism Spectrum Disorder Research

The Term Comorbidity Is of Questionable Value in Reference to Developmental Disorders: Data and Theory

Kaplan, Bonnie J., Dewey, Deborah M., Crawford, Susan G., Wilson, Brenda N.·2001·Journal of Learning Disabilities
DOI 10.1177/002221940103400608
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Abstract

Over the last decade, there has been an enormous increase in the number of studies evaluating the overlap of developmental syndromes or disorders in both children and adults. This overlap of symptoms is often referred to as comorbidity, a term we criticize in this article because of its unsubstantiated presumption of independent etiologies. The premise of this article is that discrete categories do not exist in real life, and that it is misleading to refer to overlapping categories or symptoms as "comorbidities." We illustrate our point by presenting data from 179 school-age children evaluated with rigorous research criteria for seven disorders: reading disability (RD), attention-deficit/hyperactivity disorder (ADHD), developmental coordination disorder (DCD), oppositional defiant disorder (ODD), conduct disorder (CD), depression, and anxiety. Fully 50% of this sample met the criteria for at least two diagnoses. The children with ADHD were at higher risk of having at least a second disorder compared to the children with RD. Overall, the high rates of overlap of these behavioral, emotional, and educational deficits in this broadly ascertained sample support the idea that the concept of comorbidity is inadequate. We discuss the concept of atypical brain development as an explanatory idea to interpret the high rate of overlap of developmental disorders.

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  • With regards to the association between learning disorders and mental health disorders, co-morbidity is the rule, not the exception.

    “With regards to the association between learning disorders and mental health disorders, co-morbidity is the rule, not the exception (34,35).”

    From Disorder of written expression and dysgraphia: definition, diagnosis, and management (2020) · cites this paper as [34]

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Authors
Kaplan, B. J., Dewey, D. M., Crawford, S. G., & Wilson, B. N.
Affiliations
University of Calgary (CA)
ORCID
Venue
Journal of Learning Disabilities
Publisher
SAGE Publications
Published
2001-11
Volume
34
Issue
6
Pages
555-565
ISSN
  • 0022-2194 (ISSN-L)
  • 1538-4780
DOI
10.1177/002221940103400608
OpenAlex
W2014067452
Cited by
230
References
61
Citations by year
2026: 6 · 2025: 6 · 2024: 7 · 2023: 6 · 2022: 8 · 2021: 10 · 2020: 15 · 2019: 7 · 2018: 8 · 2017: 9 · 2016: 4 · 2015: 8 · 2014: 11 · 2013: 11 · 2012: 12
FWCI
4.61
Type
journal article
Language
en
Open access
closed
Licence
journals.sagepub.com/page/policies/text-and-data-mining-license (tdm)
Locations
  • Journal of Learning Disabilities (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Social Sciences › Psychology › Neuropsychology and Physiological Psychology › Developmental and Educational Neuropsychology
  • Health Sciences › Medicine › Psychiatry and Mental health › Attention Deficit Hyperactivity Disorder
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Autism Spectrum Disorder Research
Keywords
comorbidities, developmental disorders, diagnostic overlap, reading disorders, attention deficit hyperactivity disorder, developmental coordination disorder, oppositional defiant disorder, conduct disorder, depression, anxiety, atypical brain development, elementary school students
MeSH terms
Adolescent, Adult, Attention Deficit Disorder with Hyperactivity, Child, Child Behavior Disorders, Developmental Disabilities, Diagnosis, Differential, Dyslexia, Female, Humans, Male, Neuropsychological Tests, Psychometrics, Psychomotor Disorders, Reproducibility of Results, Comorbidity, Causality, Attention Deficit and Disruptive Behavior Disorders

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