Paper of the Month: Identifying neuropsychological subgroups in children with ADHD

"This paper was selected because it has made a very important
advancement in our understanding of heterogeneity in normal
development and development of neuropsychiatric disorders. These
findings offer great promise for increased accuracy of diagnosis in children
with ADHD and other childhood neuropsychiatric disorders which could, in
turn, lead to the development of more effective treatment strategies."

- Mary Stenzel-Poore, PhD
Senior Associate Dean for Research

This month's featured paper is from the laboratories of Joel Nigg and Damien Fair, and is titled, "Distinct neuropsychological subgroups in typically developing youth inform heterogeneity in children with ADHD." It was published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS). The research in this paper was conducted by investigators in the OHSU Departments of Behavioral Neuroscience and Psychiatry, the University of Iowa, and the Indian Institute of Technology in Ropar.*

Drs. Nigg and FairAttention Deficit Hyperactivity Disorder (ADHD) is a common childhood disorder characterized by attentional problems and hyperactivity. ADHD is typically diagnosed in the elementary school years and can continue to cause significant life impairment through adolescence and adulthood. Symptoms include difficulty staying focused and paying attention, difficulty controlling behavior, and hyperactivity. Treatments can relieve many of the disorder's symptoms, and allow people to live productive lives; however, there is no cure.

Previous studies have shown that ADHD is related to various neuropsychological and cognitive weaknesses. Prior reports by investigators in the Nigg and Fair Labs and elsewhere have also shown that children with ADHD vary widely in their performance on such measures, which include verbal working memory, attention span, and executive functioning; some children appear to have marked problems, other children may be 'normally developing' in terms of their cognition.

"Lacking from previous research has been a formal description of this type of variety or 'heterogeneity' among children with ADHD," said paper co-author Joel Nigg, PhD, Professor, Department of Psychiatry. "In our paper, we attempted to clarify neuropsychological heterogeneity in a large dataset of typically developing youth and youth with ADHD."

Using a new mathematical method in a large sample of children with ADHD, the researchers from the Nigg and Fair laboratories, led on this project by the Department of Behavioral Neuroscience's Damien Fair, PhD, found distinct profiles of neuropsychological or cognitive abilities in both the ADHD group and in the typically developing group. "By comparing these profiles, we provide new insights into how the variety of cognitive development and weakness in ADHD may be understood," said paper lead author Dr. Fair.

The method and results also may provide a model for developing more valid subtypes for both ADHD and for other behavioral and psychiatric syndromes. If so, Dr. Nigg said this should eventually lead to more accurate assessment, prediction of outcome, and identification of needed rehabilitation services.

Drs. Nigg and Fair indicated that "the future is promising" in that their approach can be applied to a wide range of commonly studied measures in children with developmental conditions, including behavioral and symptom measures, clinical assessments, cognitive and physiological measures, and brain imaging and genetic measures. "We can also begin to look at how stable the types we identified are over time—something our group is currently doing," added Dr. Nigg.

*Paper Authors

Damien Fair (a,b,c); Deepti Bathula (a,d); Molly Nikolas (e); and Joel Nigg (a,b)


a - OHSU Departments of Behavioral Neuroscience
b - OHSU Department of Psychiatry
c - OHSU Advanced Imaging Research Center
d - Department of Computer Science and Engineering, Indian Institute of Technology Ropar, Rupagnar, India
e - Department of Psychology, University of Iowa


The School of Medicine newsletter spotlights a recently published faculty research paper in each issue. The goals are to highlight the great research happening at OHSU and to share this information across departments, institutes and disciplines. The monthly paper summary is selected by Associate Dean for Basic Science Mary Stenzel-Poore, PhD.

More Published Papers

The entire list of OHSU papers published this month is here