Research suggests that 25% of people with autism are not diagnosed. The reason for that may be within the disability's very name: Autism Spectrum Disorder (ASD). We use the word "spectrum" because of the wide range of symptoms, skills, and levels of disability that occur within the ASD diagnosis.

In addition to the spectrum of symptoms, ASD has characteristics similar to other disabilities, which can lead to misdiagnosis.

If you are an adult who thinks you may have autism, this article will address:

• What is High-Functioning Autism (HFA), and what role does it play in underdiagnosis?
• Symptoms of ASD
• Similar disabilities that often lead to misdiagnoses
• Why do clinicians misdiagnose women more often than men?
• Does race play a role in underdiagnoses?
• Therapies available to adults with autism
• Your first step to receiving an accurate diagnosis

What is High-Functions Autism (HFA)?

"High-functioning autism" (HFA) isn't an official medical diagnosis. HFA is the term used to describe autistic people who can speak, read, write, and handle basic life skills independently. People with HFA can often perform well in school, score high on IQ tests, and communicate effectively.

Since there is such a large spectrum with different levels of disability for people with ASD, those who fall into the higher-functioning category can often be undiagnosed or misdiagnosed well into adulthood.

What are the key symptoms of ASD?

A diagnosis of ASD includes an assessment of intellectual disability and language impairment.

Common symptoms include:

• Finding it hard to understand other people's emotions
• Anxiety about social situations
• Difficulty in making friends
• Often being misunderstood and appearing to be blunt or even rude
• Taking words and phrases too literally
• Having intense anxiety over any changes in the daily routine
• Avoiding eye contact
• Repetitive tendencies and behavior

On a more personal level, adults with ASD may:

• Have always wanted a best friend but never found one
• Invent their own words to describe things
• Repeatedly make involuntary noises, even in quiet places
• Prefer to spend leisure time playing individual games and sports, where everyone works for themselves instead of working toward a common goal on a team.

What disabilities are often confused with autism?

Similar symptoms can span several diagnoses. Unfortunately, that means the initial diagnosis is not always accurate. According to a 2019 study, 10.3% of adult participants were diagnosed with ADHD before receiving a diagnosis of autism.

A separate study in 2020 showed that adults who were diagnosed with ASD had previously been diagnosed with:

• anxiety disorders (20%)
• depressive disorders (11%)
• obsessive-compulsive disorder (OCD) (9%)
• bipolar disorder (5%)
• schizophrenia spectrum disorder (4%)

Does gender play a role in misdiagnosis or underdiagnosis?

A growing field of research suggests that women are better at masking their autistic characteristics and are thus underdiagnosed. Common forms of masking include:

• Forcing eye contact
• Rehearsing jokes or phrases before a conversation
• Reflecting social behaviors of others
• Mirroring expressions and gestures of others

Does race play a role in misdiagnosis or underdiagnosis?

In a 2019 study of 4,500 children identified as having ASD symptoms, 25% had not been diagnosed. These children were primarily Black and Hispanic males. The Organization for Autism Research reported that a 2007 study found that African-American children on the autism spectrum are 5.1 times more likely to be misdiagnosed with behavior disorders before they are correctly diagnosed with autism.

How is autism treated?

There is no cure for autism; however, there are many therapeutic options that help, including:

• Speech-language therapy
• Occupational therapy
• Social skills training
• Sensory integration therapy
• Cognitive behavioral therapy (CBT)

While medications cannot cure autism, doctors often use medicine to treat individual symptoms of ASD.

If you suspect you may have ASD, learn about screening and testing options through the Autism Society. Qualified clinicians can make the appropriate diagnosis.

Ability Central also has a library of information, including:

• Autism quick facts
• What to do after receiving a diagnosis
• Support groups
• Service Locator