Autism Journal Club
Data-driven identiﬁcation of subtypes of executive function across typical development, attention deﬁcit hyperactivity disorder, and autism spectrum disorder
Sarune Savickaite will be presenting paper by Vaidya et al (2020) Background: Impairment of executive function (EF), the goal-directed regulation of thoughts, actions, and emotions, drives negative outcomes and is common across neurodevelopmental disorders including attention deﬁcit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). A primary challenge to its amelioration is heterogeneity in symptom expression within and across disorders. Parsing this heterogeneity is necessary to attain diagnostic precision, a goal of the NIMH Research Domain Criteria Initiative. We aimed to identify transdiagnostic subtypes of EF that span the normal to impaired spectrum and establish their predictive and neurobiological validity. Methods: Community detection was applied to clinical parent-report measures in 8–14-year-old children with and without ADHD and ASD from two independent cohorts (discovery N = 320; replication N = 692) to identify subgroups with distinct behavioral proﬁles. Support vector machine (SVM) classiﬁcation was used to predict subgroup membership of unseen cases. Preliminary neurobiological validation was obtained with existing functional magnetic resonance imaging (fMRI) data on a subsample (N = 84) by testing hypotheses about sensitivity of EF subgroups versus DSM categories. Results: We observed three transdiagnostic EF subtypes characterized by behavioral proﬁles that were deﬁned by relative weakness in: (a) ﬂexibility and emotion regulation; (b) inhibition; and (c) working memory, organization, and planning. The same tripartite structure was also present in the typically developing children. SVM trained on the discovery sample and tested on the replication sample classiﬁed subgroup membership with 77.0% accuracy. Split-half SVM classiﬁcation on the combined sample (N = 1,012) yielded 88.9% accuracy (this SVM is available for public use). As hypothesized, frontal-parietal engagement was better distinguished by EF subtype than DSM diagnosis and the subgroup characterized with inﬂexibility failed to modulate right IPL activation in response to increased executive demands. Conclusions: The observed transdiagnostic subtypes reﬁne current diagnostic nosology and augment clinical decision-making for personalizing treatment of executive dysfunction in children.