Autism in adults may present with different symptoms than in children. Autism symptoms in adults may include difficulty making conversation, social anxiety, and limited interest in only a few activities.

Autism spectrum disorder (ASD) is one of the most common neurodevelopmental disorders.

In most cases, autistic people receive a diagnosis in childhood, usually after the age of 4 years. However, some autistic adults are not diagnosed in childhood, even if their symptoms are more severe.

For an autistic person who does not receive a diagnosis in childhood, receiving an ASD diagnosis later in life may be helpful for many reasons. In particular, it can provide better access to services and support.

However, many adults learn to live with the symptoms, and this can make diagnosis difficult.

This article discusses the signs and symptoms of ASD in adulthood and what to do if a person would like a diagnosis.

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The information below provides examples of symptoms of autism in adults. However, autistic people will not usually have all the signs and symptoms mentioned below, and they may experience other symptoms that are not included.

There may be some similarities between ASD and other disorders, such as attention deficit hyperactivity disorder (ADHD), but the signs and symptoms of ASD vary from person to person.

Social interactions and communication

Autistic people may find some aspects of communication and social interaction challenging. They may have difficulty relating to people and understanding their emotions.

Symptoms of ASD relating to social interactions and communication include:

  • difficulty making conversation
  • difficulty making or maintaining close friendships
  • discomfort during eye contact
  • difficulty understanding sarcasm or idioms
  • lack of inflection when speaking
  • trouble understanding facial expressions and body language
  • problems reading the emotions of others
  • challenges with regulating emotions
  • social anxiety

Restrictive or repetitive behavior

Autistic adults may have inflexible thought patterns and behaviors and may carry out repetitive actions.

Examples include:

  • making involuntary noises, such as repetitive throat-clearing
  • having a reliance on daily routines and difficulty dealing with change
  • experiencing the need to arrange items in a specific order

Interests and activities

Autistic people may have an intense interest in one particular topic. They may also talk about the topic they love frequently and for a long time.

Autistic people may also:

  • have a limited interest in only a few activities
  • have a preference for solitary activities
  • have superior abilities in a particular field, such as mathematics
  • excel in certain subjects, including maths, art, science, or music
  • be strong auditory or visual learners
  • be able to learn things in detail
  • be able to remember information for a long time

Sensory processing

Autistic adults may have a hypersensitivity to sensory stimulation, such as sounds or smells that do not seem to bother others or bright lights.

Symptoms of autism in adult females

The symptoms of ASD can differ across sexes. Research from 2020 states that some females may seem able to cope better with social situations compared to males, as their symptoms may be more subtle and masked.

‘Masking’ means that a person has adapted their behavior to suppress signs of autism in social situations. They may have also developed living and communication skills allowing them to live independently. This can make it more challenging to diagnose ASD.

Autistic females may also be quieter, hide their feelings, and show fewer signs of repetitive behaviors.

Learn more about the key symptoms of autism in females.

Seeking an ASD diagnosis as an adult can be challenging for several reasons:

  • People who did not receive a diagnosis in their younger years may have milder symptoms, which can be more difficult to recognize. At times, such people may never get a diagnosis.
  • If people have been living with ASD for some time, they may be better at masking the signs and symptoms.
  • Research shows that one of the common diagnostic tests for autism in adulthood, the ADOS-2, may be fairly reliable. However, a doctor needs to recognize a person’s symptoms to refer them to testing.

Is there a test for ASD in adults?

Clinicians have developed different tests that can help diagnose ASD in adults. A 2023 paper states that the gold standard diagnostic assessment tool for autism is ADOS-2.

However, the authors also state that diagnostic procedures do not always align with the preferences of the autistic community or the neurodiversity paradigm.

It is also not clear how reliable diagnostic tests for autism are. The reasons for this include:

  • Researchers who look at the reliability of ASD tests often use a small number of study participants.
  • Not many research studies on testing for adult ASD include enough participants from historically underserved groups, such as people of color or people who are LGBTQIA+. This means the results of studies looking at ASD testing methods may not represent a true population of autistic adults.
  • Many clinicians may not be familiar with the signs of ASD in adulthood. This is especially true if the patient’s symptoms are not severe or if the patient also has other conditions, for example, anxiety.

How to begin a diagnosis process

Adults who suspect they or a loved one might be autistic can do a self-assessment test for adults. A person can find these tests online. While they cannot give a diagnosis, the tests are a good starting point.

A person seeking a diagnosis can take the results of such a test to a primary care doctor who will try to determine whether ASD may be present by:

  • enquiring about the symptoms, both current and during childhood
  • observing and interacting with the person
  • speaking to a loved one (with permission)
  • checking for other physical or mental health conditions that may be causing symptoms

If no underlying physical condition can explain the symptoms, the doctor may refer the person to a psychiatrist or a psychologist to make an ASD diagnosis.

If symptoms are not present in childhood but begin in adolescence or adulthood, this may indicate a cognitive or mental health condition other than ASD.

It may be difficult to find a specialist who can diagnose ASD in adults. Individuals who would like a diagnosis for themselves or a loved one may need to research to find a provider with experience diagnosing autistic adults.

Another option is to speak to a developmental pediatrician or child psychiatrist willing to see adult clients.

Benefits of diagnosis

Not every undiagnosed autistic adult may want or need a diagnosis. It is important to respect the needs and preferences of the individual. For those who prefer it, a diagnosis may offer several advantages.

  • It may provide an explanation for the challenges an autistic individual may be experiencing.
  • It may give family members, friends, and colleagues a better understanding of ASD.
  • It may open up access to services and benefits, including in the workplace or education environments.
  • It may replace an incorrect diagnosis, such as ADHD.

Living with ASD may be hard for some autistic adults. They may experience challenges with social interactions, get fixated on routines, or experience sensitivities to light or sound.

Many of the same symptoms that appear in autistic children may also exist in adults. However, adults experiencing these symptoms may find it difficult to live independent, day-to-day lives as a result.

A study on services and outcomes in autistic adults showed that 27% of autistic participants were unemployed. Autistic adults may also have more limited options for support services than autistic children. In the same study, 25% of autistic participants reported not getting enough support services.

Some autistic adults experience high intelligence, strong memory, an ability to think “outside the box,” and strong knowledge in particular areas. Other traits can include being observant, resilient, and having a strong sense of fairness and justice.

For many autistic people, ASD is an essential part of their identity and does not require support. For those autistic adults who experience more challenges, increased access to the following may help:

Education

Learning more about autism can give autistic individuals and their loved ones or carers a greater understanding of the condition.

It can also help an autistic person feel validated and find solutions that work for them.

Friends and family can help reduce stress and be more compassionate by accessing available learning opportunities.

Therapy

Autistic people may have higher rates of co-occurring conditions, such as anxiety or depression, than those in the general population.

Autistic people may benefit from seeing a therapist if they are experiencing anxiety, work stress, or feelings of isolation.

Therapists can introduce people to methods such as cognitive behavioral therapy. This may help with challenges that may be more particular to ASD, such as having rigid thoughts. Therapy may take place either individually or in a group or family setting.

Taking steps to improve mental health inequality can also help underserved autistic adults get the counseling they may need.

Vocational rehabilitation

Vocational rehabilitation can help autistic people cope with career-related challenges. It allows them to explore the possibility of further education, volunteering, or job changes.

Some autistic people may find their workplaces uncomfortable if they are too noisy, too bright, or require a long commute.

Employers can take steps to support neurodiversity in the workplace. For example, they can make appropriate accommodations for autistic employees. Many resources are available, including from the Employer Assistance and Resource Network on Disability Inclusion.

Autistic people can thrive in the right workplace and with adequate support.

Peer support

Some autistic people may find it helpful to connect with other autistic people who may be experiencing similar things. A person can do this through online groups and forums, or at face-to-face support meetings.

Interacting with other autistic adults may give an autistic person new ideas about things they can do in their own lives. It can also expose a person to more resources.

Many autistic people advocate for taking a more active role in their own support services. A growing body of evidence shows that access to autistic peers can positively benefit an autistic person’s life.

Medication

Certain prescription medications can help people manage and alleviate symptoms associated with ASD, such as depression and anxiety.

The following are commonly asked questions about autism.

What is “high functioning” autism in adults?

Some people may use the term “high functioning” autism to refer to autistic individuals who do not display the stereotypical symptoms of autism. It can refer to those whose living skills and communication skills allow them to live independently.

However, the term is not a clinical diagnosis and may be problematic.

What is an autistic meltdown in adults?

Autistic people may have difficulty regulating their emotions. They may experience times of high levels of anxiety or distress in a particular situation or environment.

People may refer to this as a “meltdown.” It is important to understand that a person is not having a temper tantrum during these times.

During a “meltdown,” a person may experience feeling overwhelmed by emotional stress, senses, or information. They can experience extreme anger, sadness, and fear. They may also have difficulty with thinking and memory.

Can adults be autistic and not know it?

It is possible for adults to be autistic without realizing it. Those who did not receive a diagnosis when they were children may have milder symptoms or have learned to mask the signs and symptoms.

For some autistic people, getting a diagnosis of ASD in adulthood can provide relief, validation, and access to some support services for those who require them. For others, a diagnosis may not be necessary.

Adults who suspect that they may be autistic and would like a diagnosis can speak with their doctor. A medical professional can provide advice and guidance on the next steps.

As awareness of ASD in adulthood increases, finding the right support services and doctors who can recognize the signs and symptoms should become easier.