It is common for people to wonder about the difference between ADHD and autism. You might be trying to understand your own experience, support a loved one, or make sense of overlapping symptoms.
Some people have both ADHD and autism. Others have one but relate to traits of the other. That is why getting the right support often starts with understanding how they compare, how they connect, and how they can show up differently in each person [1].
In this guide, we will explain:
Getting the right diagnosis and support starts with clarity. A professional assessment can help you understand what is going on and what might help.
ADHD stands for attention deficit hyperactivity disorder. It affects attention, activity levels and self-control. People with ADHD may find it hard to focus, stay still, follow instructions or manage time. Some are more hyperactive or impulsive, while others mainly struggle with attention and organisation [2].
Autism is a lifelong developmental condition that affects how people communicate and experience the world. It is sometimes called autism spectrum disorder (ASD). People with autism may have differences in social communication, strong interests, a need for routine, or sensitivities to sound, light or touch.
Both ADHD and autism are neurodevelopmental conditions. They are both lifelong, but how they show up can change over time [3].
It is possible to have both conditions. This is known as a dual diagnosis or co-occurrence. But even when someone only has one, it is common to see traits of the other. That is why assessment should always look at the full picture.
If you are looking for help with focus, time management or attention, understanding ADHD can be a useful first step. Learn more about ADHD meaning and how it affects day-to-day life.
No. ADHD is not autism, and it is not considered part of the autism spectrum. They are separate conditions with their own diagnostic criteria.
Still, it is easy to see why people get confused. ADHD and autism can share some traits like trouble with focus, sensory sensitivity, social challenges or needing structure. This overlap can lead people to ask questions like is ADHD on the spectrum or is ADHD a form of autism [1].
The answer is no. But that does not mean they cannot exist together. Research shows that many people have both ADHD and autism.
Some experts believe the overlap between autism and ADHD is more common than previously thought. That is why awareness is growing, and why understanding the full range of neurodivergent traits is so important when exploring diagnosis and support [4].
Here are some key differences between the two conditions:
|
Characteristic |
ADHD |
Autism |
|
Social interaction |
May interrupt or miss cues due to impulsivity or inattention |
May avoid eye contact, struggle with reciprocal interaction |
|
Communication |
May speak quickly, jump topics, lose track of conversation |
May speak literally or with flat tone, delayed speech common |
|
Repetitive behaviours |
Rare. May hyperfocus, but not usually repetitive actions |
Common. Stimming, fixed routines or repeated behaviours |
|
Executive functioning |
Core difficulty. Affects planning, memory and task follow-through |
Also present but linked to broader developmental traits |
|
Attention and hyperactivity |
Key traits include distractibility, impulsivity and restlessness |
Not core features. May focus intensely but not show hyperactivity |
Some of the most common overlapping traits include:
These overlaps can be confusing. If several traits are present and affecting your life, it may help to consider autism and ADHD together.
Yes. ADHD and autism can co-occur. This is sometimes called AuDHD. It describes people who meet the criteria for both conditions and live with a distinct mix of traits.
Studies suggest that around 30 to 50 percent of autistic people also have signs of ADHD. Likewise, many people diagnosed with ADHD later discover they also meet the criteria for autism [2].
This combined experience is different from just having similar traits. It can affect learning, relationships and how you respond to daily life. If you are unsure whether you relate to ADHD, autism or both, speaking to a professional is the best next step. You can explore your next steps with an ADHD assessment.
Sensory overload can happen more quickly in people with both conditions. You may feel overwhelmed by sound, light, movement or touch. This can link closely to anxiety. Learn more in our guide to ADHD and anxiety.
Tasks may feel harder to start, organise or complete. You might feel up and down in your ability to cope with energy, motivation and focus changing day to day.
People with AuDHD often hide both ADHD and autistic traits to fit in. This can lead to emotional exhaustion or feeling like you are always performing [5].
It may feel easier to be social than it actually is. You might mask social difficulties or find conversations hard to track. Over time, this can affect how confident you feel in relationships. Read more about ADHD and relationships.
“High-functioning” usually refers to people who appear to manage daily life well, but it can be misleading. Many adults with both conditions struggle silently with emotional regulation, time management and social exhaustion [8].
Common signs include:
If you relate to this, you can learn more about adult ADHD and what might help.
ADHD and autism are often missed in women. Traits may be masked or misunderstood. Women are more likely to internalise symptoms, overcompensate or feel anxious about being “too much.”
Common traits in women include:
Many women reach burnout before ever being diagnosed. To understand more about how this shows up, read our guide to ADHD in women.
In the Republic of Ireland, ADHD and autism assessments are separate. ADHD is usually assessed by a psychiatrist. Autism assessments often involve a multidisciplinary team [6].
HealthHero offers private ADHD assessment and treatment. While we do not offer formal autism assessment, our team can help you explore your traits and talk through your options. For more information on an ADHD assessment in Ireland, get in touch with our team.
ADHD and autism can overlap but they are not the same. Each person’s experience is unique, and support should reflect that.
If you are ready to get clarity, HealthHero offers trusted assessments, ongoing care and advice from expert clinicians.
Contact HealthHero for an ADHD assessment and personalised support. We are here to help you understand what is going on and what can help.