Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects how people socially connect with others. About 25 years ago, ASD was considered a rare disorder. Now, it is highly prevalent, affecting one in 68 children, and resulting in a growing adult population of affected individuals (Christensen et al., Citation2016). Outside our practice, we are all likely to know or have met someone with ASD. Many have medical and psychiatric comorbidities, which, together with the core features of ASD, result in significant personal, familial, and societal costs throughout the lifespan. The increased prevalence of ASD and recognition of its adverse impacts has led to an explosion of research on many facets of the disorder, ranging from aetiology to treatment.
This issue of the International Review of Psychiatry presents seven articles that each provide a cutting edge review on different aspects of ASD. Each of the articles is thoughtfully written by expert researchers and clinicians in the field of ASD. Three provide an overview of some of the major inroads in the field with respect to the aetiology and early intervention of ASD. The other four articles focus on the most impairing accompanying features of ASD, psychiatric, and behavioural disorders. Most of the current research on these disorders has been conducted in children and adolescents, although research in adults is gradually emerging.
Dr. Harris sets the stage for this issue by presenting a 75-year retrospective review of Dr. Leo Kanner’s contributions to the field. This article opens with a discussion of the changing landscape of the ASD diagnostic criteria over the past 35 years, and is followed by a synthesis of scientific discoveries in several major domains, ranging from developmental neuroimaging to animal models. Dr. Harris highlights how Kanner’s initial observations of ASD being an ‘innate’ disorder have become the foundation for groundbreaking genetic research. The article includes several moving quotes by Kanner that reflect his dedication and advocacy for children and adolescents with developmental disabilities.
We know that genes have a compelling influence on the development of ASD. Dr. Constantino presents seven important advances in the field of genetic and family studies. He discusses how ASD develops when multiple neurodevelopmental ASD liability genes collide early in development, even before symptoms appear. Non-ASD risk factors such as sub-clinical familial presentations and psychiatric and developmental comorbidities (e.g. ADHD, motor difficulties) can superimpose on ASD risk genes, contributing to development of the syndrome. Atypical social visual orientation patterns in infancy can also predict ASD, which opens the door for developing novel treatment targets to reduce ASD risk.
Considerable evidence shows that early intervention treatments have efficacy in improving developmental outcomes in children at risk for and children with ASD. Rooted in principals of neuroscience, these treatments are intended to stimulate brain connectivity through learning experiences that target multiple developmental domains, social, behavioural, language, and cognitive functioning. Dr. Landa reviews the literature on early intervention for young children with ASD. She highlights the importance of initiating treatment in the second year of life when atypical developmental patterns begin to manifest, but also reminds us that, while treatment data show moderate-to-large effect sizes, response rates are influenced by various child, parent, and clinician factors.
Dr. Rosen reports that up to 40% of children with ASD have a psychiatric disorder, aggravating social difficulties and causing impairment in multiple domains. The most well-studied disorders in children and adolescents are ADHD and anxiety disorders. Fewer studies of psychiatric disorders have been carried out in adults, although preliminary evidence indicates high rates of anxiety and depression in this population. Rosen et al. emphasize two important points when assessing psychopathology—the first is the need to tease apart overlapping symptoms between ASD and psychiatric disorders, and the second is to recognize ambiguous symptom presentations of psychopathology. Because we have so few validated psychiatric measures for the ASD population, recognition of psychiatric conditions requires a careful and comprehensive diagnostic evaluation.
Dr. Keefer et al. provide an in-depth and comprehensive review of the wide variety of psychosocial treatments that have emerged for internalizing disorders associated with ASD. This is one of the first reviews published to date which includes both cognitive behavioural interventions and third wave treatments such as mindfulness-based interventions. Another unique feature of this review is its focus on treatment of both anxiety and depressive disorders, as well as novel treatments that target transdiagnostic constructs such as emotion dysregulation and intolerance of uncertainty. Overall, the most robust evidence is for CBT in the treatment of anxiety disorders in youth with ASD, although psychosocial treatments for other conditions are promising.
Dr. Goel et al. provide an update on pharmacologic trials that target both the core features of ASD as well as the accompanying psychiatric and behavioural comorbidities. Findings from this review indicate that randomized control trials are still quite limited, and we still do not have efficacious treatments for core ASD symptoms. Furthermore, limited pharmacological treatments exist for select psychiatric comorbidities, such as anxiety and depression. Exciting novel treatments, however, are being actively studied, including those that target the pathophysiological mechanisms implicated in ASD such as the glutamate, cholinergic, and oxytocin systems. Important considerations for future research are discussed, such as the need to address heterogeneity and develop sensitive outcome measures.
Finally, the last two papers in this series focus on the management of severe behavioural and psychiatric disturbances in individuals with ASD, critical for practitioners at the front lines of care. Dr. Newcomb and Dr. Hagopian discuss the profound impact of problem behaviours (e.g. aggression, self-injurious behaviours) on quality-of-life for the child and family. The authors state that children with severe problem behaviours are often in crisis and, over time, families become exhausted, distressed, and face significant financial strain. Treatment of these severe behaviours requires a transdisciplinary treatment approach that integrates behavioural interventions, with psychosocial and pharmacotherapeutic ones. Often, the behaviours are socially mediated, and require a precisely orchestrated treatment approach.
With the rising prevalence of ASD and high rates of psychiatric comorbidities in ASD, the demand for acute psychiatric services is high; yet, access to more intensive treatment, such as inpatient hospitalization for the treatment of problem behaviours, is limited. Dr. McGuire and Dr. Siegel discuss the current state of psychiatric inpatient treatment services for individuals with ASD, noting that currently there are only about 15 specialized inpatient units in the country for individuals with developmental disabilities and acute psychiatric and behavioural issues. These units implement biobehavioural approaches that offer comprehensive psychiatric, behavioural, medical, psychosocial, and developmental treatments. Although more specialized units are gradually sprouting, in most parts of the country, typical inpatient units are expected to serve these children, but their care is hampered by a lack of resources, as well as insurance constraints on length of stay.
In summary, this collection of papers is intended to highlight the exciting new discoveries in the field of ASD. While science is rapidly advancing, clinicians have a responsibility to bring evidence to the bedside, and support families along this difficult journey. Mental health clinicians, in particular, are likely to experience more referrals to evaluate and treat individuals with ASD and associated co-occurring psychiatric conditions. Equally important is training the next generation of mental health providers to provide high quality care for individuals with ASD and their families. I would like to thank the authors and reviewers for their outstanding contributions to this issue. I hope that the knowledge gained will translate into better clinical care for individuals with ASD.
Disclosure statement
No potential conflict of interest was reported by the author.
References
- Christensen, D. L., Baio J., Van Naarden Braun, K., Bilder, D., Charles, J., Constantino, J. N., … Yeargin-Allsopp, M. (2016). Prevalence and characteristics of autism spectrum disorder among children aged 8 years — Autism and developmental disabilities monitoring network, 11 sites, United States, 2012. Surveillance Summaries. 65(3):1–23. doi:10.15585/mmwr.ss6503a1