Autism or ADHD? Understanding the Differences – and When It Could Be Both

Perhaps you've wondered whether you might have ADHD. Or autism. Or you've read about both and found yourself thinking, "Actually, parts of both sound like me."

You're certainly not alone in finding the distinction difficult.

Autism and Attention Deficit Hyperactivity Disorder (ADHD) are both neurodevelopmental conditions. They are distinct, but some characteristics can overlap, and it is possible to be both autistic and have ADHD.

Understanding the similarities and differences can be a useful first step if you're considering an assessment.

How are autism and ADHD different?

ADHD is typically associated with differences in areas such as attention, activity levels, impulsivity, organisation and executive functioning.

An autistic person may experience differences in social communication and interaction, alongside patterns relating to interests, routines, predictability, sensory experiences and repetitive behaviours.

That sounds relatively straightforward on paper. In everyday life, however, the distinction isn't always so obvious.

Where can autism and ADHD look similar?

There are several experiences that can occur in both.

Social situations

Someone with ADHD might lose track of a conversation, interrupt without intending to, or find it difficult to wait for their turn to speak.

An autistic person might find the unwritten rules of conversation difficult to interpret, need more time to process what has been said, or prefer communication that is direct and unambiguous.

From the outside, both people might simply appear to be having difficulty with conversation – but the reasons underlying that experience may be quite different.

Routine and organisation

An autistic person may find routine reassuring and experience unexpected change as particularly difficult.

Someone with ADHD might desperately want routine but find it difficult to establish or maintain because of difficulties with planning, organisation or time management.

And, of course, someone who is both autistic and has ADHD may experience both.

They might crave predictability while simultaneously finding it difficult to create it.

Interests and attention

Both autistic people and people with ADHD can become deeply absorbed in things that interest them.

Someone with ADHD may experience periods of very intense focus on an engaging activity while finding it much harder to sustain attention on something that provides less stimulation.

Autistic people may have particularly strong or focused interests that bring enjoyment, expertise, comfort or predictability.

Again, what appears similar from the outside may reflect different underlying experiences.

Sensory experiences

Sensory differences are commonly associated with autism, but people with ADHD can also experience sensitivity to their surroundings.

Noise, lighting, textures, smells or busy environments may feel distracting, uncomfortable or overwhelming.

A comprehensive assessment therefore looks at the broader pattern of someone's experiences rather than interpreting one characteristic in isolation.

What is AuDHD?

You may increasingly have encountered the term AuDHD.

It is an informal term commonly used to describe someone who is both autistic and has ADHD. It isn't a separate medical diagnosis; rather, it describes the co-occurrence of autism and ADHD.

For some adults, recognising both can help explain experiences that previously seemed contradictory.

You might, for example:

• Value routine but struggle to maintain one.
• Want predictability while also seeking novelty.
• Become deeply absorbed in particular interests but struggle to concentrate on everyday tasks.
• Want social connection while finding social interaction tiring.
• Carefully organise some areas of life while others feel chaotic.

These experiences don't mean that somebody necessarily has autism or ADHD, but they can be useful areas to explore during an assessment.

Why might one be recognised before the other?

Sometimes one condition is identified while characteristics of the other are less apparent.

A person may have developed effective ways of compensating or masking particular difficulties. Anxiety, depression or other mental health difficulties may also have been the first reason they sought professional help.

For others, the demands of adult life, university, employment, relationships, parenting or managing a household – can make longstanding differences more noticeable.

Some people therefore reach adulthood having spent many years feeling that everyday life requires considerably more effort than it seems to require for other people.

Can an online test tell me whether I have autism or ADHD?

Online questionnaires can sometimes help people reflect on their experiences, but they cannot provide a diagnosis on their own.

There is no single questionnaire, behaviour or personality trait that determines whether someone is autistic or has ADHD.

A comprehensive assessment considers your experiences across your life, including childhood and development, education, relationships, employment, everyday functioning and mental health. It also considers whether there may be other explanations for the difficulties you're experiencing.

What if I'm not sure which assessment I need?

You don't necessarily need to work that out by yourself before contacting an assessment service.

At The Beacon Hub, we provide adult autism assessments, ADHD assessments and combined autism and ADHD assessments.

Our multidisciplinary approach means we're interested in understanding the whole person rather than simply looking for a checklist of symptoms.

If you're unsure which assessment might be most appropriate, you can contact us before booking. We can explain the different assessment pathways and help you understand the options available to you.

Taking the next step

Recognising yourself in an article about autism or ADHD doesn't necessarily mean that you have either condition.

But if you've experienced longstanding differences with attention, organisation, social communication, sensory experiences, routines or managing everyday life, you may decide that understanding those experiences more fully would be helpful.

For some adults, assessment provides an explanation for experiences they have been trying to understand for many years. For others, it helps identify different explanations or support needs.

Whatever the outcome, the purpose of a good assessment should be to help you develop a clearer understanding of you.

At The Beacon Hub, we provide comprehensive online adult autism, ADHD and combined assessments across the UK. Our assessments are delivered by an experienced multidisciplinary team using a compassionate, evidence-informed and neurodiversity-affirming approach.

If you'd like to ask us a question before deciding whether an assessment is right for you, you're very welcome to get in touch.