Overlapping and Distinct Cognitive Impairments in Attention-Deficit/Hyperactivity and Autism Spectrum Disorder without Intellectual Disability

Abstract

Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are commonly comorbid, share genetic liability, and often exhibit overlapping cognitive impairments. Clarification of shared and distinct cognitive effects while considering comorbid symptoms across disorders has been lacking. In the current study, children ages 7-15 years assigned to three diagnostic groups:ADHD (n = 509), ASD (n = 97), and controls (n = 301) completed measures spanning the cognitive domains of attention/arousal, working memory, set-shifting, inhibition, and response variability. Specific processes contributing to response variability were examined using a drift diffusion model, which separately quantified drift rate (i.e., efficiency of information processing), boundary separation (i.e., speed-accuracy trade-offs), and non-decision time. Children with ADHD and ASD were impaired on attention/arousal, processing speed, working memory, and response inhibition, but did not differ from controls on measures of delayed reward discounting, set-shifting, or interference control. Overall, impairments in the ASD group were not attributable to ADHD symptoms using either continuous symptom measures or latent categorical grouping approaches. Similarly, impairments in the ADHD group were not attributable to ASD symptoms. When specific RT parameters were considered, children with ADHD and ASD shared impairments in drift rate. However, children with ASD were uniquely characterized by a wider boundary separation. Findings suggest a combination of overlapping and unique patterns of cognitive impairment for children with ASD as compared to those with ADHD, particularly when the processes underlying reaction time measures are considered separately.

Pupil dilation during visuospatial orienting differentiates between autism spectrum disorder and attention‐deficit/hyperactivity disorder

“…Taken together, the lack of correlations across groups except for cue‐ and stimulus‐evoked PD amplitudes within ASD‐ may additionally indicate an increased effort to optimize task performance in children with ASD‐ (Rondeel, van Steenbergen, Holland, & van Knippenberg, ). Nevertheless, to further examine how the LC‐NE system modulates attention and task performance future studies should examine other, and more sensitive measures of (disorder‐specific) response execution in addition to RT (Karalunas et al, ).…”

Social and delay discounting in autism spectrum disorder

“…Although our findings of greater delay discounting in ASD are contrary to some studies, existing literature is mixed. Some researchers have found evidence for greater discounting of future rewards in ASD (e.g., Carlisi et al, ; Chantiluke et al, ; Murphy et al, ), but others have found no group differences (e.g., Antrop et al, ; Demurie et al, ; Karalunas et al, & Kouklari, Tsermentseli, & Monks, in press). One possible explanation is that most studies finding differences, including ours, examined adolescents and adults, whereas most studies showing no differences included children as young as 7 or 8.…”

Sibling Recurrence Risk and Cross-aggregation of Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder

“…8 These disorders appear to share some genetic factors 9 and biological pathways, 10 although divergences in their neuro-biological, cognitive, and genetic profiles are apparent. 11–13 Although some findings may be accounted for by the co-occurrence of ADHD and ASD 13 and others by heterogeneity within the 2 conditions, 14 it remains unclear how related these disorders are etiologically. It is important to further characterize the degree of shared etiologic risk across these impairing, prevalent, and complex conditions.…”