ADHD and Autism Together in Adults: What Overlaps and What Differs

Two conditions that often travel together

ADHD and autism are both conditions that begin in childhood and continue into adult life. They are defined separately, yet they turn up in the same person often enough that clinical guidance treats the combination as common.

An expert consensus statement published in BMC Medicine describes autism as among the conditions commonly found alongside ADHD. The Centers for Disease Control and Prevention (CDC) lists hyperactive, impulsive or inattentive behavior among the other characteristics autistic people may have. The National Institute of Mental Health (NIMH) notes that some signs of autism in adults can overlap with those of ADHD.

What overlaps

The consensus statement notes that both conditions are commonly associated with social difficulties and with trouble in executive functions, the mental skills used to plan, organize and shift between tasks. From the inside, the shared ground can look like this.

• Attention: losing track of tasks, missing details, or finding it hard to move on from something absorbing
• Executive function: difficulty planning, starting, organizing and finishing, especially when a routine changes
• Sensory experience: differences in sensory sensitivities are part of how autism is described, and a review in Frontiers in Psychiatry notes that sensory processing differences can affect attention
• Social effort: conversations and group settings that take a lot of energy to manage

What differs

The same behavior can come from different places. The consensus statement gives an example. A person with ADHD may be over-talkative and dominate a conversation, speaking with energy and passion. An autistic person may be over-talkative and dominate a conversation about a special interest. Both can make the back-and-forth of conversation harder, but the authors describe the quality of the difficulty as markedly different.

Attention works the same way. The statement notes that people with ADHD tend to make careless errors because of poor concentration. For some people, concentration problems and overactivity are less evident when they are engrossed in a topic.

The Frontiers in Psychiatry review adds that ADHD is more directly linked to difficulty with inhibition, meaning holding back an action or a response. Autism is defined by differences in social communication together with restricted or repetitive behaviors and interests, including sensory differences. So the useful question is often why something happens, not only whether it happens.

Why adults are often recognized with one first

The consensus statement points to several reasons a second condition can go unnoticed for years.

• The rules changed. Earlier editions of the diagnostic manual did not allow clinicians to diagnose ADHD and autism in the same person. The current edition does
• One picture can hide the other. The statement notes that milder signs of autism may not be recognized, or may not be given priority, in a child whose ADHD-related behavior draws the attention
• The usual timing differs. The authors note that the average age of diagnosis is not the same for the two conditions, and that many people do not receive an autism diagnosis until adulthood
• Coping strategies work, at a cost. Signs of both can be masked by compensatory strategies developed over time, and the statement observes that keeping up a social front takes great effort

What an evaluation that considers both looks at

The consensus statement recommends that both conditions be considered when one of them is present, and that no single appointment or measure be treated as conclusive. It describes a comprehensive assessment as one that gathers detailed information about a person's development and how they function across settings.

For adults, the authors recommend a developmental history, provided where possible by someone who knew the person as a child. Reports from childhood, such as school reports, can be informative. NIMH likewise notes that an adult ADHD diagnosis relies heavily on past reports of behavior, and that an adult autism evaluation may include a conversation with family members about early development.

The statement also cautions evaluators not to count the same behavior twice. If talkativeness has been explained by ADHD, it should not also be counted toward autism without separate evidence. This is why an evaluation of both is more than two checklists side by side.

An evaluation is a process of gathering information. It may find one condition, both, or neither, and nobody can tell you the result ahead of time.

If you are in crisis or thinking about harming yourself, call or text 988, or call 911. Locascio Wellness does not provide emergency services.

How we can help

Locascio Wellness offers an ADHD evaluation and an autism evaluation, carried out entirely by secure video for people who are physically located in Pennsylvania, West Virginia or Arizona. If you are wondering about both, say so at the start, so we can talk through what would answer your question.

Evaluations are private-pay and are not billed to insurance, and a sliding scale is available. See what evaluations cost. An evaluation ends with the findings explained in plain language, time for your questions, and a written report. We do not prescribe medication.

The first step is the short evaluation request form or a free 15-minute consultation, which you can schedule on our booking page.

Therapy is a separate service, and you do not need a diagnosis to begin. For ongoing support with focus, organization and daily routines, therapists on our team offer ADHD therapy by video. Many adults find that understanding how their mind works makes daily life easier to plan around.