Autism Spectrum Disorder (ASD) is a term established in the 2013 publication of the DSM-5, the manual psychologists use to diagnose disorders according to specific criteria. Before this, there were different categories of disorders considered to be “autism,” and researchers felt it was more accurate and more clinically useful to describe these different disorders as existing along a spectrum of symptoms and severity.

These new guidelines required significant difficulty with two broad categories of functioning: (1) reciprocal social communication and social interaction and (2) restricted, repetitive patterns of behavior. Though these criteria allowed even mild cases to be recognized as autism, the broadness of the categories meant a very wide variety of symptoms was possible. One person with ASD can have a completely different set of challenges from another person with the same diagnosis, which can make diagnosis harder. Furthermore, these criteria can fail to adequately describe some people—especially girls and older people—who don’t exactly fit classic expectations or who have learned to mask their difficulties. Sometimes people can reach adulthood without anyone recognizing their symptoms of ASD, and, after learning their diagnosis, many people feel relief at being a bit better understood.

For these reasons, it’s important to have a thorough evaluation with a clinician who understands and can recognize all the nuances of ASD. The backbone of a strong ASD evaluation is a very detailed history of someone’s early development; that will help uncover behaviors that may have faded or been masked later on. Evaluation of cognitive skills (intelligence, memory, academic skills) helps establish strengths and weaknesses for independent functioning at home, school, and work. Executive function deficits are common in ASD, so skills these skills are required too. We use the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) to help us elicit certain social communication strengths and weaknesses, and we test more broadly for social cognition and language skills using other measures and questionnaires.