Autism Spectrum Disorder

Why High-IQ Patients with Autism or ADHD Face Elevated Risk

Individuals with an above-average IQ and high-functioning autism, especially those with co-morbid ADHD, are less likely to be diagnosed and more likely to struggle in social spheres. This represents a real health risk for this vulnerable population — one that too few physicians recognize.

Young girl playing with toy

Nearly 2 percent of children aged 8 or younger have been diagnosed with autism spectrum disorder (ASD). This statistic is well documented today. What’s surprising is that half of these children also have an average or considerably above-average IQ. What’s more, at least two-thirds of people with ASD, particularly those with a high IQ, also have attention deficit disorder (ADHD or ADD). Needless to say, it is difficult to disentangle symptoms that include social difficulties, namely the inability to understand how others are processing a situation.

In part because symptoms overlap, high-functioning, high-IQ people with ASD comprise a vulnerable population. Since they excel in certain subjects, their condition isn’t typically recognized until they are much older, often resulting in extreme sadness and social isolation.

The tools that most clinicians use to assess ASD are adequate for identifying people who are severely impaired, but not those who are higher-functioning. These individuals are commonly left to try and get by in mainstream schools, universities, and workplaces. Their irregular behavior may be mistaken for laziness by teachers and parents who hover and take charge of organizing their lives. It isn’t until the child leaves home and has to manage for himself that problems arise.

[[Self-Test] Is My Child on the Autism Spectrum?]

In addition, they are frequently unable to understand social cues and how other people think. They might say things that are insulting or hurtful without even realizing it. Sometimes, it is easier to explain to a child with ASD how to factor a quadratic equation than it is to explain why a joke is funny in one situation and not in another. Regardless of IQ, these individuals will continue to struggle socially. In fact, a UK study1 found that the rate of suicide among higher functioning individuals with ASD is nine times that of the general population.

My book Smart but Stuck (#CommissionsEarned) provides helpful context for understanding young adults with ADHD and high IQs. But clearly more training is needed for physicians, psychologists, and educators to better identify and support high-functioning, high-IQ children with ASD, particularly as they get older.

This content came from the ADDitude webinar by Thomas E. Brown, Ph.D., titled “A Careful Diagnosis: Expert Guidelines for Getting an Accurate ADHD Evaluation“. That webinar is available for free replay here.

Thomas E. Brown, Ph.D., is a member of ADDitude’s ADHD Medical Review Panel.

[[Self-Test] Autism Spectrum Disorder Symptoms in Adults]


Sarah Cassidy, Paul Bradley, Janine Robinson Carrie Allison, Meghan McHugh, Simon Baron-Cohen. “Suicidal ideation and suicide plans or attempts in adults with Asperger’s syndrome attending a specialist diagnostic clinic: a clinical cohort study.” The Lancet Psychiatry. Vol. 1, Issue 2. (Jul. 2014)

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