Why High-Functioning Autism Is Hard to Define

High-functioning autism (HFA) is neither an official diagnosis nor is there an agreed-upon definition of what the term means. In the broadest sense of the term, high-functioning autism may mean any of the following:

• A person with relatively mild symptoms which, despite their mildness, are significant enough to merit an autism spectrum diagnosis
• A person with autism whose IQ is higher than 70
• A person with autism who is successfully navigating a typical school or work environment
• A person who is able to mask symptoms of autism and can "pass" for neurotypical
• A person who, at one point, had an Asperger's syndrome diagnosis—a diagnosis that has not been officially in use since 2013

Adding to the confusion is the fact that many people with autism may be bright and accomplished yet have severe symptoms (such as anxiety and sensory dysfunction) that significantly impact their daily functioning.

HFA vs. Asperger's Syndrome

Until 2013, many people who might be said to have high-functioning autism were diagnosed with either Asperger's syndrome or PDD-NOS (pervasive developmental disorder not otherwise specified). 

But, there are differences that set those two diagnoses apart:

• Asperger's syndrome was a distinct diagnosis which described a person of average or higher-than-average intelligence and age-appropriate language skills who also had significant social and communication challenges.
• PDD-NOS was a catch-all diagnosis. Often understood to mean the same thing as "high-functioning autistic," it really incorporated individuals at all functional levels whose symptoms didn't fully correlate with classic autism.

Perhaps more significantly, people with Asperger's syndrome often had different symptoms than people with higher IQs and autism. For example, anxiety was often a symptom of Asperger's syndrome but not one shared by everyone who might be described as having HFA.

HFA and Level 1 Autism

Autism spectrum disorder is a single diagnosis that encompasses many people who are very different from one another. So, to clarify these differences, the DSM-5 also includes functional levels. People who are bright and verbal are generally given the diagnosis of Level 1 ASD.

Still, the distinction doesn't offer a clear characterization of what Level 1 ASD actually is. For example:

• People with Level 1 ASD can show affection, complete daily tasks, and use age-appropriate language, reading, and math skills. On the other hand, they may not be able to hold eye contact, maintain a conversation, engage in play, or pick up on social cues. 
• People with Level 1 ASD can have significant speech and language delays but may be able to take part in an inclusive academic program because of their age-appropriate academic skills.  
• People with Level 1 ASD can have relatively mild speech and social delays but may have severe sensory issues which make it impossible for them to take part in an inclusive academic program. 
• People with Level 1 ASD can have severe anxiety, learning disabilities, and sensory challenges but still have age-appropriate speech and exceptional abilities in music, math, and engineering. 

Determining Support Needs

While few people with high-functioning autism need help with using the toilet or basic hygiene, they may very well need a good deal of support in other settings. For example, a very bright individual with severe sensory issues, anxiety, and perseveration might actually have a more difficult time in the workplace than a less intelligent individual with less anxiety and fewer sensory issues.

What's more, a "lower-functioning" individual might spend most of his day in a supported setting where the possibility of dangerous interactions is almost zero. Meanwhile, the high-functioning individual may need to navigate a world full of complex and hazardous situations.

Navigating the Challenges

Autism is a puzzle—not because individuals with autism are so puzzling, but because the ever-changing definitions of autism can lead to a lack of clarity.

Not only are the definitions changing but so are the social expectations that make high functioning autism so challenging. In the past, face-to-face communication was the key to personal success; today, many people with social challenges are more than capable of interacting with others online, making friends through social media, and even holding down a job at a distance.

Some businesses like Google are hiring people with high-functioning autism because of their unique abilities, while others cannot imagine hiring a person with compromised social skills.