Understanding the Overlap Between Autism, Attention-Deficit/Hyperactivity Disorder, and Anxiety

Autistic traits vary from person to person, impacting how individuals are identified as being autistic and when they receive their diagnosis, and they can also influence how individuals respond to different interventions. One factor contributing to this variability is the coexistence of autism with other conditions like anxiety and attention-deficit/hyperactivity disorder (ADHD). Estimates suggest that 40-60% of autistic children also have anxiety and/or ADHD.

When autistic children have either anxiety or ADHD, it can make things more challenging for them in several ways. For instance, they may find it harder to manage their emotions, or they may face greater difficulties with things like sleeping and eating habits. It also impacts their academic performance. Because of this, understanding the impact of co-occurring anxiety and ADHD on the lives of autistic individuals is crucial. Currently, there’s limited knowledge about how these conditions affect autistic children, especially in early childhood. Furthermore, we lack insights into their influence on commonly used brain and behavioral measures employed in research and clinical trials.

To bridge these gaps, Kimberly Carpenter, PhD, assistant professor in the Duke Center for Autism and Brain Development, launched the Autism HERO study in 2021. This study takes a comprehensive approach, combining parent reports with play-based and brain assessments to examine how co-occurring anxiety and ADHD affect autistic children aged 4 to 7 years. Importantly, several challenges exist in understanding the unique impact of ADHD and anxiety on autistic individuals. These include difficulty differentiating between the conditions due to overlapping features, absence of guidelines for assessing anxiety and ADHD in autistic individuals, and reliance on measures created and standardized for non-autistic populations.

To address these challenges, Dr. Carpenter is collaborating with experts in ADHD diagnosis in autism (Drs. Naomi Davis, Julia Schechter, and Rachel Aiello from Duke University) and anxiety in autism (Dr. Connor Kerns from the University of British Columbia) to develop new diagnostic guidelines for co-occurring anxiety and ADHD in young autistic children. These guidelines will be coupled with assessments across various domains to better understand the distinct effects of anxiety and ADHD on clinical presentation, behavioral outcomes, and the neurobiology of autism. This research aims to support the development of early detection and intervention methods for co-occurring anxiety and ADHD in young autistic children, with the ultimate goal of improving the quality of life for all autistic individuals.