Commentary: Developmental origins of autism and ADHD – a commentary on Johnson et al. (2015)

Abstract

Autism (autistic spectrum disorder, ASD) and attention deficit hyperactivity disorder (ADHD) are two highly prevalent neurodevelopmental disorders. Current estimates for autism exceed 1% For ADHD, the 2013 US‐based life time prevalence figure is 11%. Both disorders are also highly heritable. Intriguingly, approximately 50% of children with ASD also meet criteria for ADHD. Between their high heritability and comorbidity, some have wondered whether these two seemingly different disorders might in fact be related at some deep neurobiological level. The notion that these two disorders may be related is surprising when one considers the fact that autism generally appears in the first 1–2 years of life, whereas it is virtually impossible to identify ADHD during this time frame; indeed, inattentiveness and hyperactivity tend to be traits that are shared by nearly all toddlers, making a stable diagnosis of ADHD virtually impossible until early childhood (although a reliable diagnosis can generally be made during the preschool period). Like many neurodevelopmental disorders, early identification and early treatment are essential to easing the life time burden of these disorders. Of course, early treatment is predicated on early identification and it is for this reason that the review article by Johnson and colleagues is so intriguing, as it sets out to determine whether these disorders can be identified in the infancy period. It also raises a number of puzzling issues that remain undiscussed.

Changing ASD-ADHD symptom co-occurrence across the lifespan with adolescence as crucial time window: Illustrating the need to go beyond childhood

“…This may possible be explained by the non-crystallized nature of problem behavior in most atypically developing children at that age. That is, the manifestation of ADHD and ASD symptoms is less outspoken in young children, which may hold in particular for (future onset of) ADHD (Möricke et al, 2013;Nelson, 2015;Sonuga-Barke and Halperin, 2010). Core features of ADHD and ASD, such as reduced self-regulation or theory of mind, involve neural systems that are too immature to already show delay or dysfunction in early life (Mungas et al, 2013;Sullivan et al, 2015).…”

The Comorbidity of ADHD and Autism Spectrum Disorders (ASDs) in Community Preschoolers

“…Although autism tends to appear during the first 1-2 years of life, ADHD is nearly impossible to diagnose along this period. Hyperactivity and inattentiveness are features shown by almost all toddlers, thus making ADHD very difficult to diagnose reliably until early childhood (although it is often possible during the preschool period) [71]. Children demonstrate dramatic gains in control processes between the ages of 3 and 6.…”

Response to uncertainty in developmental origins of health and disease research: commentary on Nomura et al. (2022)

“…We appreciate the comments of Gilman, Govender, Augustin, and Yu (2023) on our paper and their acknowledgement of its importance in highlighting the significance of this area of research. Further, their acknowledgment that the primary results of our study are in a range that is similar to those from other published studies of children exposed to highly stressful environmental events emphasizes the validity of our findings and the important extension of our results to children experiencing these events in utero.…”