In an article published in the February 2012 edition of the Journal of Attention Disorders,
Richard Mattison, MD and Susan Dickerson Mayes, PhD described
relationships among learning disability, executive function and
psychopathology in a clinical sample of children with ADHD. They found
that problems with executive function were associated with learning
disabilities but not with psychopathology, and reflected on the
implications of their findings for clinical practice.
Several
studies have shown that children with ADHD are at increased risk for
learning disabilities. This is explained in part by the fact that
problems with attention, working memory, processing speed, and other
executive function skills are characteristic of both learning
disabilities and ADHD. It is also known that many children with ADHD
have other co-occurring psychiatric disorders, including anxiety
disorders, major depressive disorders and conduct disorders. The
prevalence of these psychiatric disorders in children with learning
disabilities has not been extensively studied. Nor was it known how the
presence of learning disabilities is associated with the risk of other
psychiatric disorders in children with ADHD.
A statistical
analysis of the records of 595 children with ADHD revealed that the
presence of learning disabilities was not significantly associated with
the presence or type of psychiatric illness in these children. And while
the presence of learning disabilities was not predictive of Full Scale
IQ scores, it was associated with differences in specific measures of
executive function, including indices of working memory and processing
speed. An analysis of academic performance scores showed, as expected,
that children with ADHD who also had learning disabilities scored lower
on all measures of achievement than children without learning
disabilities.
Based on these findings, the researchers concluded
that the core deficits in executive function appear to be more closely
associated with learning disabilities and problems with academic
achievement than with psychopathology in children with ADHD.
Reflecting
on their findings, the researchers suggested that clinicians assess all
patients with ADHD for the presence of learning disabilities, since
over 73% of the participants in their study had a co-occurring learning
disability. The authors also advised clinicians to avoid reliance on
abbreviated IQ measures or on Full Scale IQ scores, since these fail to
reveal the executive function deficits that characterize children with
ADHD and learning disabilities.
Richard Mattison is Professor of
Psychiatry in the Division of Child and Adolescent Psychiatry at Stony
Brook University. Susan Mayes, Ph.D., is Chief Psychologist and
Professor in the Department of Psychiatry at Penn State College of
Medicine.
