Heterogeneity in ADHD: Neurocognitive predictors of peer, family, and academic functioning

ABSTRACT

Childhood attention-deficit/hyperactivity disorder (ADHD) is associated with impairments in peer, family, and academic functioning. Although impairment is required for diagnosis, children with ADHD vary significantly in the areas in which they demonstrate clinically significant impairment. However, relatively little is known about the mechanisms and processes underlying these individual differences. The current study examined neurocognitive predictors of heterogeneity in peer, family, and academic functioning in a well-defined sample of 44 children with ADHD aged 8–13 years (M = 10.31, SD = 1.42; 31 boys, 13 girls; 81% Caucasian). Reliable change analysis indicated that 98% of the sample demonstrated objectively-defined impairment on at least one assessed outcome measure; 65% were impaired in two or all three areas of functioning. ADHD children with quantifiable deficits in academic success and family functioning performed worse on tests of working memory (d = 0.68 to 1.09), whereas children with impaired parent-reported social functioning demonstrated slower processing speed (d = 0.53). Dimensional analyses identified additional predictors of peer, family, and academic functioning. Working memory abilities were associated with individual differences in all three functional domains, processing speed predicted social functioning, and inhibitory control predicted family functioning. These results add to a growing literature implicating neurocognitive abilities not only in explaining behavioral differences between ADHD and non-ADHD groups, but also in the substantial heterogeneity in ecologically-valid functional outcomes associated with the disorder.

KEYWORDS:

• ADHD
• Social
• Family
• Academic
• Functioning
• Heterogeneity

Acknowledgements

The authors thank Erin Lunsford, Paula Aduen, Dr. Hillary Schaefer, and the CLC-V undergraduate research assistants.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary Material

Supplemental data for this article can be accessed here.

Notes

¹ Conservatively computed based on Cohen’s d effect sizes as the percentage of non-overlap between the ADHD and non-ADHD population distributions (i.e., the percentage of children with ADHD scoring outside the typically developing range) as recommended (Zakzanis, 2001).

Additional information

Funding

This work was supported by the National Institute of Mental Health [grant number R34 MH102499-01]; and by a UVa Curry School of Education Foundation grant (PI: Kofler) from the Galant Family.