Adults with autism spectrum disorder: Updated considerations for healthcare providers

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Release date: August 1, 2019
Expiration date: July 31, 2020
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Children with autism spectrum disorder (ASD) eventually grow up and need to make the transition from pediatric services to adult. This is a diverse patient population.


  • Autism is becoming more common, with most recent statistics showing at least 1 in 59 children affected.
  • Asperger syndrome is now included in the category of ASD, with possible implications for coverage of care.
  • Some children with ASD get better as they get older, but many do not, and some do not receive a diagnosis until adulthood.
  • Diagnosing ASD in adults can be difficult and involves specialists from multiple disciplines.
  • Social support is important. Community programs and behavioral therapies can help. Drug therapy has not been rigorously tested and is not approved for use in adults with ASD. Caregivers may also need support.



Autism spectrum disorder (ASD) has increased significantly over the past 40 years. Even in the past 2 decades, the prevalence increased from 6.7 per 1,000 in 20001 to 14.6 per 1,000 in 2012—1 in 59 people.2 Of those with ASD, 46% have an intelligence quotient (IQ) greater than 85, meaning they are of average or above-average intelligence.1

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As more children with autism become adults, understanding this condition across the life span grows paramount. While many studies have focused on understanding how diagnosis and treatment can help young children, few have focused on adults with autism and how primary care teams can better assist these individuals. However, this is changing, with studies of the benefits of employment programs and pharmacologic treatment, and reproductive health needs of adults with ASD. Here we provide an updated review of ASD in adult patients.


As the scientific understanding of autism has expanded, revisions in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5),3 published in 2013, have paralleled these advances. For many adult patients with autism who were evaluated as children, these revisions have led to changes in diagnosis and available services.

Autistic disorder, Asperger syndrome, and autism spectrum disorder: Past and present terminology and def-initions

In the previous edition (DSM-IV-TR, published in 2000),4 autistic disorder and Asperger syndrome were separate (Table 1). However, DSM-5 lumped autistic disorder and Asperger disorder together under the diagnosis of ASD; this leaves it to the clinician to specify whether the patient with ASD has accompanying intellectual or language impairment and to assign a level of severity based on communication deficits and restrictive behaviors.

The shift in diagnosis was worrisome for some, particularly for clinicians treating patients with DSM-IV Asperger syndrome, who lost this diagnostic label. Concerns that patients with Asperger syndrome may not meet the DSM-5 criteria for ASD were validated by a systematic review showing that only 50% to 75% of patients with DSM-IV autistic disorder, Asperger syndrome, or pervasive developmental disorder not otherwise specified (PDD-NOS) met the DSM-5 criteria for ASD.5 Most of those who no longer met the criteria for ASD carried a DSM-IV diagnosis of Asperger syndrome or PDD-NOS or had an IQ over 70.5 Nevertheless, these individuals may struggle with impairing symptoms related to repetitive behaviors or communication or may be affected by learning or social-emotional disabilities. Additionally, even if they meet the criteria for ASD, some may identify with the Asperger syndrome label and fear they will be stigmatized should they be classified as having the more general ASD.6,7

Although future revisions to the DSM may include further changes in classification, grouping adults with ASD according to their functional and cognitive ability may allow for pragmatic characterization of their needs. At least 3 informal groupings of autistic adults have been described that integrate cognitive ability and independence8:

  • Those with low cognitive and social abilities, who need lifelong support
  • Those with midrange cognitive and social limitations but who can complete their work in special education classes; they often find employment in supervised workshops or other work with repetitive tasks
  • Those who have greater cognitive ability and some social skills; they may proceed to college and employment and live independently.


Prognostication for people with ASD remains an area of research. Some adults experience a reduction in symptoms as they age, with significant improvements in speech and, sometimes, modest improvements in restrictive and repetitive behaviors.9,10

Nevertheless, autism remains a lifelong disorder for many. Adults may still require significant support and may experience impairment, particularly in social interaction.10 In longitudinal studies, only 15% to 27% of patients with ASD are characterized as having a positive outcome (often defined as variables related to independent function, near-normal relationships, employment, or a quantified reduction in core symptoms), and many experience significant dependency into adulthood.10–13

IQ has been cited as a possible prognostic factor,10,13 with an IQ below 70 associated with poorer outcome, although an IQ above 70 does not necessarily confer a positive outcome. Less-severe impairment in speech at baseline in early childhood also suggests better outcomes in adulthood.10

As we see more adults with autism, studies that include both children and adults, such as the Longitudinal European Autism Cohort, will be important to characterize the natural history, comorbidities, and genetics of ASD and may help provide more specific predictors of disease course into adulthood.14


Next Article:

Where have all the children gone? Intentional communities for adults with autism

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