Adults with autism spectrum disorder: Updated considerations for healthcare providers

ACHIEVING A DIAGNOSIS FOR ADULT PATIENTS WITH SUSPECTED AUTISM

While many patients are recognized as having autism in early to mid-childhood, some adults may not receive a formal diagnosis until much later in life. Those with fluent language and normal-range IQ are likely to be overlooked.¹⁵ People with ASD may have had mild symptoms during childhood that did not impair their functioning until demands of daily life exceeded their capacities in adulthood. Alternatively, parents of a child with newly diagnosed ASD may realize that they themselves or another adult family member also show signs of it.

The UK National Institute of Health and Care Excellence suggests that assessment should be considered if the patient meets psychiatric diagnostic criteria and one of the following:

• Difficulty obtaining or sustaining employment or education
• Difficulty initiating or sustaining social relationships
• Past or current contact with mental health or learning disability services
• History of a neurodevelopmental or mental health disorder.^15,16

Currently, diagnosis typically involves a multidisciplinary approach, with psychiatric assessment, neuropsychological testing, and speech and language evaluation.¹⁷ Providers may need to refer patients for these services, sometimes at the patient’s request, if previous mental health misdiagnoses are suspected, if patients report symptoms or impairment consistent with ASD, or if benefits, services, or accommodations, such as a coach in the workplace, are needed.

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Diagnosing ASD in adults can be difficult, given that the gold-standard diagnostic tests such as the Autism Diagnostic Observation Schedule-2 (ADOS-2)¹⁸ and the Autism Diagnostic Interview-Revised (ADI-R)¹⁹ are typically used to diagnose autism in children. However, Module 4 in the ADOS-2 was developed for adolescents and older patients with fluent language and has shown at least moderate power to distinguish adults with ASD from those without ASD.^18,20

An initial psychiatric assessment should include a thorough history taken from the patient and, if applicable, the patient’s caregiver, as well as a psychiatric interview of the patient. Neuropsychological testing should include evaluation of cognitive function, social functioning (using the ADOS-2 for adults without intellectual disability, the ADI-R, or both), and adaptive functioning (using the Vineland Adaptive Behavior Scales, second edition²¹).

Evaluation of speech and language is particularly important in patients with limited language ability and should include both expressive and receptive language abilities. Serial testing every few years, as is often recommended in childhood, may help establish the pattern of impairment over time.

Comorbid psychiatric disorders are common

Many people with ASD also have other psychiatric disorders,^17,22 which clinicians should keep in mind when seeing an adult seeking evaluation for ASD.

Attention-deficit/hyperactivity disorder is present at higher rates in patients of average intellectual function with ASD than in the general population.²³

Anxiety disorders, including obsessive-compulsive disorder, were found to often coexist with autism in a sample of adults with autism without intellectual disability,^24,25 and approximately 40% of youths with ASD have at least 1 comorbid anxiety disorder.²⁶

Mood disorders are also prevalent in adults with ASD, with a small study showing that 70% of adults with DSM-IV Asperger syndrome had at least 1 depressive episode in their lifetime.²⁷

BEHAVIORAL AND PHARMACOLOGIC THERAPIES FOR THE ADULT PATIENT

Treatment of adults with ASD should be individualized based on the challenges they are facing. Many, including those with average or above-average intelligence, struggle with interpersonal relationships, employment, housing, other health conditions, and quality of life.²⁸ Thus, behavioral services and programs should be tailored to help the patient with current challenges (Table 2).

Services and medications for adults with ASD are discussed below. These will vary by individual, and services available may vary by region.

Historically, vocational and social outcomes have been poor for adults with ASD. It is estimated that most larger universities may be home to 100 to 300 students with ASD. To combat isolation, the University of California, Los Angeles, the University of Alabama, and others provide special support services, including group social activities such as board games and individual coaching.⁸ Nevertheless, half of the students with autism who attend institutions of higher learning leave without completing their intended degree.²⁹ Many still struggle to establish meaningful friendships or romantic relationships.²⁹

Planning for a transition of care

Healthcare transition planning is important  but is strikingly underused.³⁰ Individual providers, including adult psychiatrists, vary in their level of training and comfort in diagnosing, treating, and monitoring adults with autism. Youths with ASD are half as likely to receive healthcare transition services as other youths with special healthcare needs.³¹

Pediatric providers, including pediatric psychiatrists, developmental behavioral specialists, and pediatric neurologists, may be best equipped to treat young adult patients or to refer patients to appropriate generalists and specialists comfortable with autism-specific transition of care. The question of eligibility for services is important to patients and families during the transition period, with many parents and professionals unaware of services available to them.³² Receiving adequate transition services is enabled by having a medical home during childhood—that is, a comprehensive, centralized medical record, culturally competent care, interaction with schools, and patient access to clear, unbiased information.³¹

Ideally, in our experience, transitioning should be discussed well before the child ages out of the pediatric provider’s practice. If necessary, healthcare transition services should include 4 components:

• Discussing the switch to a new physician who treats adults
• Discussing changing healthcare needs as an adult
• Planning insurance coverage as an adult
• Encouragement by the physician for the child to take age-appropriate responsibility for his or her healthcare.^31,33

Tools such as the Got Transition checklist from the National Health Care Transition Center can provide support during this process.³⁴