ADHD and ASD: distinct brain patterns of inhibition-related activation?

Ariadna Albajara Sáenz,Leila Salvesen,Gianfranco Passeri,Laurent Victoor,Thomas Villemonteix,Mathilde Septier,Eric Willaye,Nicolas Deconinck,Véronique Delvenne,Simon Baijot,Pierre Defresne,Hubert Raeymaekers,Peter Van Schuerbeek,Isabelle Massat,Philippe Peigneux

doi:10.1038/s41398-020-0707-z

Abstract

Attention-deficit/hyperactivity (ADHD) and autism spectrum (ASD) disorders often co-occur. In both cases, response inhibition deficits and inhibition-related atypical brain activation have been reported, although less consistently in ASD. Research exploring the overlap/distinctiveness between ADHD and ASD has significantly increased in recent years, but direct comparison of the inhibition-related neuronal correlates between these disorders are scarce in the literature. This study aimed at disentangling the shared and specific inhibitory brain dysfunctions in ASD and ADHD. Using functional magnetic resonance imaging (fMRI), brain activity was compared between children with ADHD, ASD and typically developing (TD) children aged 8–12 years during an inhibition stop-signal task, using stringent inclusion criteria. At the behavioural level, only children with ADHD exhibited inhibition deficits when compared with the TD group. Distinct patterns of brain activity were observed during successful inhibition. In children with ADHD, motor inhibition was associated with right inferior parietal activation, whereas right frontal regions were activated in children with ASD. Between-group comparisons disclosed higher middle frontal activation in the ASD group compared with the ADHD and the TD groups. Our results evidence different patterns of activation during inhibition in these two disorders, recruiting different regions of the fronto-parietal network associated to inhibition. Besides brain activity differences, behavioural inhibition deficits found only in children with ADHD further suggest that reactive inhibition is one of the core deficits in ADHD, but not in ASD. Our findings provide further evidence contributing to disentangle the shared and specific inhibitory dysfunctions in ASD and ADHD.

Highlights

Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) have distinct core diagnostic criteria but often co-occur
IQ was significantly higher in the typically developing (TD) group compared with the ADHD (p = 0.01), which is typical in this population[9]
The hyperactivity score was significantly higher in the ADHD group compared with that of the TD group (p < 0.001)

Summary

Introduction

Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) have distinct core diagnostic criteria but often co-occur. ADHD is characterized by impairing levels of inattention and/or hyperactivity–impulsivity, and ASD is defined by deficits in social communication and interaction, and the presence of restricted, repetitive behaviours, interests or activities[1]. Since the publication of the DSM-V, both diagnoses should be given when both ASD and ADHD diagnostic criteria are met[1]. ADHD is the most common comorbid psychiatric condition in referred populations of youths with ASD, with studies reporting comorbidity rates as high as 71%2,3. ASD traits are common in children and adolescents with ADHD, with 12.4% having an ASD diagnosis[4]. An increasing number of studies are investigating the overlap and distinctiveness between these disorders at the cognitive, clinical and biological level, to determine whether they are sufficiently distinct to be considered separate disorders, or rather represent the extremes of an underlying continuum[5]

Objectives

Methods

Results

Conclusion