Autism in Adults: Presentation, Diagnosis, and Management

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects an individual’s social interactions and communication.1 In recent decades, the prevalence of ASD has increased from 1 in every 150 children to 1 in every 36.2 While most people with ASD are diagnosed during childhood, individuals with ASD who have subtle symptoms and/or are able to use compensation strategies and coping mechanisms may not receive a diagnosis until adulthood.1 Many of the diagnostic criteria, diagnostic tests, and interventions for ASD emphasize children. Understanding how to recognize, diagnose, and manage ASD in adults is critical to being able to provide optimal care for these patients.

Autism Spectrum Disorder Diagnostic Criteria

As described in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), the diagnostic criteria for ASD include 5 main components1:

  1. Persistent deficits in social communication and social interaction;
  2. Restricted, repetitive patterns of behavior, interests, or activities;
  3. Symptoms must be present in the early developmental period; 
  4. Symptoms must cause clinically significant impairment in social, occupational, or other important areas of functioning; and
  5. These disturbances are not better explained by intellectual disability or global developmental delay.

Social Deficits

The social deficits of ASD are categorized as difficulties with social-emotional reciprocity, nonverbal communication, and relationships. Social-emotional reciprocity impairments include having difficulty initiating conversations, being unable to carry on a typical back-and-forth conversation, and not responding in emotionally sensitive or appropriate ways.1 Nonverbal communication deficits include trouble making eye contact or using body language, difficulty using or understanding gestures, and a lack of facial expressions.1 Individuals with ASD may have a lack of interest in or trouble making friends and maintaining friendships. They also may have trouble adjusting their behavior to suite various social contexts.1

Restricted, Repetitive Behaviors

Behaviors that are characteristic of ASD include the following1:

  • Repetitive motor movements (such as hand flapping or finger flicking), use of objects (such as spinning coins), and speech (such as repeating words and phrases used by others);
  • Rigid adherence to schedules and resistance to change;
  • Having highly restricted, fixated interests; and 
  • Exhibiting increased sensitivity to sensory stimuli.

For a patient to meet the criteria for an ASD diagnosis, these symptoms need to have been present since early development.1 Although the ASD symptoms may not become fully evident until later in life, ASD does not first develop in adulthood.1 The ASD diagnostic criteria in DSM-V require that deficits limit or impair a person’s everyday functioning, such as the ability to excel in school, maintain a job, or live independently.1

Symptoms of Autism in Adults

Adults with ASD generally have similar signs and symptoms as children. These usually center around poor communication strategies and impaired social functioning. However, adults with ASD may have learned to “mask” or cover up some of those symptoms to fit in and shield themselves from social repercussions associated with ASD. Behaviors that might be used to mask ASD symptoms include the following3,4:

  • Mimicking others’ mannerisms and styles; 
  • Mimicking small talk; 
  • Altering speech volume;
  • Rehearsing conversation topics before interacting with others;
  • Making eye contact despite discomfort doing so; and
  • Not standing too close to others. 

Masking ASD traits may be more prevalent in females than in males.4 One reason more males than females are diagnosed with ASD earlier in life may be that females have more effective masking strategies.4 Masking can help individuals with ASD to succeed in social situations, but it can also lead to anxiety and exhaustion.4 

Examples of potential symptoms of ASD in adults include the following3:

  • Difficulty with expressive communication: Lack of a filter when speaking, flat affect, monotonous tone of voice, difficulty maintaining conversations, avoidance of or particularly intense eye contact, difficulty identifying thoughts/feelings;
  • Difficulty interpreting communication: Trouble understanding nonverbal cues and others’ intentions, thoughts and feelings; and 
  • Restricted interests and behaviors: Insistence on routine and stress when routines are disrupted, intense interest in a particular hobby, object, or area of study.

In terms of repetitive behaviors, adults with ASD often learn to hide hand flapping and other motor movements that are characteristic of younger patients, but they may adapt such behaviors by rubbing their fingers together inside a pocket, tapping their feet, or repetitively rubbing their hands on their thighs.3 In adults, some internal symptoms might not be outwardly apparent, such as social anxiety, social phobia, or exhaustion after social activities3 Adults with ASD also may3:

  • Have trouble organizing, planning, or maintaining focus;
  • Irregular sleep patterns; and
  • Clumsy gait or poor physical coordination.

Diagnosing Autism in Adults

Challenges to accurately diagnosing ASD in an adult include the need to determine if symptoms were present during the patient’s early development period, an adult’s ability to mask or compensate for ASD symptoms, and the high rates of co-occurring psychiatric and medical disorders, with symptoms overlapping those of ASD.5,6 Prompt diagnosis is important because even in adults, earlier diagnosis is associated with improved quality of life.7 The optimal approach to diagnosing ASD in an adult has not yet been established. A request for evaluation for ASD may be initiated by the patient or by a family member/caregiver. The clinician may need to talk to the patient’s family members to determine if symptoms of ASD have been present since the patient’s childhood.8 A referral to a psychiatrist or neuropsychiatrist who specializes in ASD often is necessary because those clinicians are best equipped to make the diagnosis.3,8

The DSM-5-TR diagnostic criteria for ASD are used for both children and adults. However, additional measures may be needed to help establish an accurate diagnosis in an adult patient. Questionnaires used to help clarify an ASD diagnosis in adults include the Autism Spectrum Quotient (AQ), the abridged AQ-10, the Social Responsiveness Scale-Adult version, and the second edition of the Autism Diagnostic Observation Schedule (ADOS-2).6

The ADOS-2 is considered a gold-standard instrument for diagnosing ASD in adults.5 It’s a standardized test for measuring communication deficits. It consists of 4 modules that can be administered based on the patient’s age; module 4 is intended for adolescents and adults with fully developed speech.5 

The ADOS-2 focuses on verbal and nonverbal communication deficits. The test is highly sensitive —  it does a good job of detecting ASD in adults who actually have the condition — but there are many false positives, especially if the patient has psychotic symptoms.5 

Management of Autism in Adults

Treatment of ASD specifically for adults remains poorly studied, and services for adults with ASD lag far behind those available for children.9 Optimized treatment strategies have not been established.6 Autism spectrum disorder in adulthood presents heterogeneously, and treatment strategies are mostly individually based. 

Psychosocial Interventions

Behavioral-based treatments such as social skills training and applied behavior analysis have been used to effectively address the core symptoms of ASD in children, and may be appropriate for adults.4,6 Cognitive-behavior therapy and mindfulness-based therapy approaches have been used with some success for adults with ASD.6 These strategies have been used to improve communication as well as emotional processing to reduce anxiety and stress that arise from societal and social expectations that are not intuitive to understand.4,6 Vocational support such as training in interview skills and supported employment may be beneficial for adults with ASD but research to support a specific vocational strategy is lacking.6

Receiving an ASD diagnosis as an adult can be overwhelming. It is important for adults with ASD to have access to support and resources to understand their condition and feel less isolated. Support groups can be useful for the patient as well as for the family members of an adult who has been recently diagnosed with ASD.3 Online support groups can allow patients to share their experiences without having to face the anxiety of in-person interactions.3


Other than the antipsychotics aripiprazole and risperidone for treating ASD-associated irritability in children of certain ages, the US Food and Drug Administration has not approved any medications for treating ASD.10 However, people with ASD often also have comorbid psychiatric symptoms and disorders, and receive medication to address these conditions. Specifically, an adult with ASD may benefit from being prescribed the following medications6: 

  • Stimulants or atomoxetine for attention-deficit/hyperactivity disorder;
  • Antidepressants for anxiety, depression, or obsessive-compulsive disorder;
  • Mood stabilizers for bipolar disorder; or
  • Antipsychotics for irritability and impulsivity. 

Author Bio

Hannah Actor-Engel, PhD, earned a BS in Neural Science at New York University and her PhD in Neuroscience at the University of Colorado. She is a multidisciplinary neuroscientist who is passionate about scientific communication and improving global health through biomedical research

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