Autism spectrum disorder

Autism spectrum disorder (ASD) is a lifelong neurodevelopmental condition that is being viewed increasingly as an example of neurologic and cognitive variation among people. It is clinically very heterogeneous. It is associated with disabilities and everyday challenges, but may also be associated with cognitive strengths and talents.

Children and adults with ASD have social communication and interaction difficulties and show restricted, repetitive, and stereotyped patterns of behaviors, interests, or activities.

Social communication impairments and ASD behaviors are present during early childhood, but may only become manifest later (e.g., due to increasing impairment).

ASD is a genetic disorder of brain development, but nongenetic factors are also likely to contribute to the phenotype and its heterogeneity.

The aims of treatment are to maximize functional independence and quality of life, and to minimize distress by supporting learning, social communication, and cognitive skills, and by managing any co-occurring physical or mental health problems.

Long-term outcome in adulthood is variable. Many people live either in 24-hour care or with community support (approximately 20%); however, some people with ASD live independent lives (approximately 15%), and some have jobs and families.

Autism spectrum disorder (ASD) is characterized by persistent impairments in social communication, and restricted, repetitive, and stereotyped patterns of behaviors, interests, or activities.[1]American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 5th ed., text revision (DSM-5-TR). Washington, DC: American Psychiatric Publishing; 2022. Abnormal development is present during early childhood, but may only become manifest later.[2]World Health Organization. International Classification of Diseases 11th revision (ICD-11). Chapter 6: mental, behavioural or neurodevelopmental disorders. Jan 2022 [internet publication]. https://icd.who.int/en There may be a history of language disorder or language delay (single-word or phrase speech delay) and some children lose previously acquired language skills (regression).[3]Rogers SJ. Developmental regression in autistic spectrum disorders. Ment Retard Dev Disabil Res Rev. 2004;10(2):139-43. http://www.ncbi.nlm.nih.gov/pubmed/15362172?tool=bestpractice.com [4]Parr JR, Le Couteur A, Baird G, et al. Early developmental regression in autism spectrum disorder: evidence from an international multiplex sample. J Autism Dev Disord. 2011 Mar;41(3):332-40. http://www.ncbi.nlm.nih.gov/pubmed/20711649?tool=bestpractice.com Conversely, some children may develop language at a very early age and have relatively "adult-like" speech. Children who meet the criteria have a diagnosis of "autism spectrum disorder", additionally qualified by level of severity.[1]American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 5th ed., text revision (DSM-5-TR). Washington, DC: American Psychiatric Publishing; 2022. Approximately 20% to 30% of children develop epilepsy, and between 40% and 80% have intellectual disability (characterized by impaired global intelligence and subsequent impaired social functioning); note that the term "intellectual disability" as used in this topic does not refer to specific learning disorders or disabilities, such as dyslexia or dyscalculia, which may also occur in ASD.[5]Volkmar FR, Nelson DS. Seizure disorders in autism. J Am Acad Child Adolesc Psychiatry. 1990 Jan;29(1):127-9. http://www.ncbi.nlm.nih.gov/pubmed/2295565?tool=bestpractice.com [6]Levy SE, Mandell DS, Schultz RT. Autism. Lancet. 2009 Nov 7;374(9701):1627-38. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2863325 http://www.ncbi.nlm.nih.gov/pubmed/19819542?tool=bestpractice.com [7]Baird G, Simonoff E, Pickles A, et al. Prevalence of disorders of the autistic spectrum in a population cohort of children in South Thames: the Special Needs and Autism Project (SNAP). Lancet. 2006 Jul 15;368(9531):210-5. http://www.ncbi.nlm.nih.gov/pubmed/16844490?tool=bestpractice.com [8]Woolfenden S, Sarkozy V, Ridley G, et al. A systematic review of two outcomes in autism spectrum disorder - epilepsy and mortality. Dev Med Child Neurol. 2012 Apr;54(4):306-12. https://onlinelibrary.wiley.com/doi/full/10.1111/j.1469-8749.2012.04223.x http://www.ncbi.nlm.nih.gov/pubmed/22348343?tool=bestpractice.com [9]Besag FM. Epilepsy in patients with autism: links, risks and treatment challenges. Neuropsychiatr Dis Treat. 2017 Dec 18;14:1-10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5739118 http://www.ncbi.nlm.nih.gov/pubmed/29296085?tool=bestpractice.com [10]Maenner MJ, Shaw KA, Bakian AV, et al. Prevalence and characteristics of autism spectrum disorder among children aged 8 years - autism and developmental disabilities monitoring network, 11 Sites, United States, 2018. MMWR Surveill Summ. 2021 Dec 3;70(11):1-16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8639024 http://www.ncbi.nlm.nih.gov/pubmed/34855725?tool=bestpractice.com Others have ability in the average or above average range. However, many people have an uneven cognitive profile, and show relative cognitive strengths and weaknesses on cognitive testing. In addition to the core symptoms of ASD, the majority of people have coexisting difficulties (e.g., difficulties with sleep or eating). Many young people and adults with ASD have mental health problems such as anxiety and depression. People with ASD may have multiple coexisting problems or conditions concurrently; these associated conditions are often more challenging to manage than ASD itself, but can be a target for intervention or treatment.[11]Maskey M, Warnell F, Parr JR, et al. Emotional and behavioural problems in children with autism spectrum disorder. J Autism Dev Disord. 2013 Apr;43(4):851-9. http://www.ncbi.nlm.nih.gov/pubmed/22895777?tool=bestpractice.com