How Is High Functioning Autism Diagnosed in Adults?

How Adults Are Diagnosed with High Functioning Autism

Diagnosing Asperger in adults
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You've never really grasped small talk, and would rather talk to a computer than another human being. Does that mean you have Asperger Syndrome (AS)?  Actually, since the publication of the latest diagnostic criteria, there is no longer a diagnosis called Asperger Syndrome.  But it is perfectly possible that you are an adult who is diagnosable with a relatively mild form of autism spectrum disorder (or a similar or related disorder).

Self-Tests and Professional Evaluations

While you can start the process of diagnosis with a self-test such as the "AQ" designed in 2001 by Dr. Simon Baron-Cohen, a medical diagnosis must be performed by a medical professional. While it's not easy to find someone with experience in diagnosing autism in adults, most psychiatrists with autism experience should be able to administer appropriate tests and provide a useful diagnosis.

Dr. Shana Nichols of the Fay J. Lindner Center for Autism on Long Island in New York specializes in diagnosing and treating teens and adults with the symptoms associated with high functioning autism (Asperger Syndrome). While she uses several specific diagnostic tools to identify specific symptoms, she says that even those tools are somewhat out of date. "We've learned an enormous amount since then," she says; new tools are under development but are not yet ready for general use.

The Testing and Evaluation Process

When adults come to the Lindner Center for a diagnosis, Dr. Nichols begins her exam with an IQ test. She also administers an assessment of adaptive skills which tests the patient's ability to manage complex social situations.

"If a parent is available," says Nichols, "we administer a parent interview called the ADI (Autism Diagnostic Interview-Revised).

We're looking at current functioning and early history to get a sense of the patient's skills in social, communication and behavior domains." After all, as she says, "autism doesn't suddenly show up when you're 25, so most people with true autism showed symptoms throughout their childhood." If parents aren't available, Nichols and her colleagues ask the patient to recall their childhood, asking such questions as "Did you have a lot of friends?" and "What did you enjoy doing?"

Nichols also administers the ADOS Module IV. ADOS is the autism diagnostic observation schedule, and module four is for high-functioning verbal young adults and adults. Along with the ADI, it allows doctors to look carefully at social and communication skills and behavior. For example, says Nichols, the tests look at such questions as "Can you have a reciprocal social conversation? Are you interested in the examiner's thoughts and feelings? Do you demonstrate insight into relationships? Do you use appropriate non-verbal gestures and facial expressions? Do you have odd or over-focused interests?" The tests allow doctors to attach a grade in each domain to determine whether the patient meets the criteria for autism.

When the Diagnosis Is NOT Autism

It's not unusual, says Nichols, for a patient to come in expecting an autism diagnosis and to leave with a different diagnosis. "Distinguishing between social phobias or shyness and actual impairment with autism can be very tough for a layperson," she says. Other disorders, such as obsessive-compulsive disorder (compulsions, hoarding, needing to do things over and over), social communication disorder, or social anxiety can sometimes look like autism. If doctors do pick up on these other disorders, they can recommend appropriate therapy and/or medication.


Ami Klin, Ph.D., and Fred R. Volkmar, M.D. Asperger's Syndrome Guidelines for Assessment and Diagnosis. Yale Child Study Center, New Haven, Connecticut. Published by the Learning Disabilities Association of America, June 1995.

Interview with John Michael Carley, Executive Director, Global and Regional Asperger Syndrome Partnership (GRASP). April, 2007.

Interview with Dr. Shana Nichols, North Shore Long Island Jewish Health System, Fay J. Lindner Center for Autism. May, 2007.

Barrett SL, Uljarevic M, Baker EK, et al. The Adult Repetitive Behaviors Questionnaire-2 (RBQ-2A): A Self-Report Measure of Restricted and Repetitive Behaviors. Journal of Autism and Developmental Disorders. 2015.