Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Multicenter Study
. 2015 Nov;25(11):2062-2074.
doi: 10.1016/j.euroneuro.2015.08.010. Epub 2015 Aug 21.

Cognitive Heterogeneity in Adult Attention Deficit/Hyperactivity Disorder: A Systematic Analysis of Neuropsychological Measurements

Affiliations
Free PMC article
Multicenter Study

Cognitive Heterogeneity in Adult Attention Deficit/Hyperactivity Disorder: A Systematic Analysis of Neuropsychological Measurements

Jeanette C Mostert et al. Eur Neuropsychopharmacol. .
Free PMC article

Abstract

Attention Deficit/Hyperactivity Disorder (ADHD) in childhood is associated with impaired functioning in multiple cognitive domains: executive functioning (EF), reward and timing. Similar impairments have been described for adults with persistent ADHD, but an extensive investigation of neuropsychological functioning in a large sample of adult patients is currently lacking. We systematically examined neuropsychological performance on tasks measuring EF, delay discounting, time estimation and response variability using univariate ANCOVA's comparing patients with persistent ADHD (N=133, 42% male, mean age 36) and healthy adults (N=132, 40% male, mean age 36). In addition, we tested which combination of variables provided the highest accuracy in predicting ADHD diagnosis. We also estimated for each individual the severity of neuropsychological dysfunctioning. Lastly, we investigated potential effects of stimulant medication and a history of comorbid major depressive disorder (MDD) on performance. Compared to healthy adults, patients with ADHD showed impaired EF, were more impulsive, and more variable in responding. However, effect sizes were small to moderate (range: 0.05-0.70) and 11% of patients did not show neuropsychological dysfunctioning. The best fitting model predicting ADHD included measures from distinct cognitive domains (82.1% specificity, 64.9% sensitivity). Furthermore, patients receiving stimulant medication or with a history of MDD were not distinctively impaired. To conclude, while adults with ADHD as a group are impaired on several cognitive domains, the results confirm that adult ADHD is neuropsychologically heterogeneous. This provides a starting point to investigate individual differences in terms of impaired cognitive pathways.

Keywords: Adult ADHD; Executive function; Heterogeneity; Neuropsychology; Reaction time variability; Reward.

Figures

Figure 1
Figure 1. Differences in performance between ADHD patients and controls on measurements from several cognitive domains
Bar graphs indicate the average performance per group for each neuropsychological measure (time estimation absolute median deviation from 1000ms is not shown); error bars represent the standard error of the mean. Dark grey bars represent the healthy control group, lighter grey bars represent ADHD patient group. An asterix (*) indicates measures where patients differed significantly from controls.
Figure 2
Figure 2. Deficient test scores across participants
For each participant, deficient test scores were computed as the number of test scores that were below the score of the bottom 10% of the control group, divided by the total number of test scores of that participant and multiplied with 100%. The sections indicate the percentage of participants that had a deficient test score within a certain bin. `Mildly impaired' are participants with 1–20% deficient test scores, `impaired' are those with 20–40% deficient test scores and those with more than 40% deficient were labeled as `severely impaired'.

Similar articles

See all similar articles

Cited by 22 articles

See all "Cited by" articles

Publication types

MeSH terms

Substances

Feedback