ADHD, Autism or both? How do I know which assessment I need?  Clear Sky Therapies

“I’ve been reading about ADHD, but I also relate to a lot of information about Autism.”

“My friends think I’m autistic, but social media says it could be ADHD.”

“Do I need two separate assessments?”

These are questions we hear increasingly often at Clear Sky Therapies.

As awareness of neurodiversity has grown, many people recognise aspects of themselves in descriptions of both Attention Deficit Hyperactivity Disorder (ADHD) and Autism. This can be both reassuring and confusing. While the two conditions share a number of characteristics, they are also distinct neurodevelopmental conditions, each with their own diagnostic criteria and patterns of strengths and challenges.

Some people have ADHD.

Some people are autistic.

Some people meet the criteria for both.  More recently this has been called AuDHD, though the term is just a popular description, rather than a formal diagnosis.  For both, it remains, Autism and ADHD, and they still need consideration separately as well as how they may combine and overlap.

The purpose of a high-quality assessment is not simply to decide which label fits best, but to understand why you experience the world in the way that you do.

Why Do ADHD and Autism Look Similar?

One reason people become uncertain is that there is genuine overlap between ADHD and Autism.

Someone may experience:

• Difficulty organising and managing everyday tasks;
• Sensory sensitivities;
• Emotional dysregulation;
• Feeling different from other people;
• Becoming overwhelmed in busy environments;
• Challenges maintaining relationships;
• Difficulties at work or education;
• Anxiety and exhaustion following social situations.

Looking only at these outward experiences, it can be difficult to know which condition is responsible.

However, experienced clinicians are interested in something deeper than the behaviour itself.

They ask:

 

What is driving that behaviour?

Understanding why something happens is often far more informative than simply observing what happens.  Also when it an issue, and to what extent.

ADHD and Autism Can Sometimes Produce Similar Behaviours for Different Reasons

Imagine two people who both dislike attending large social events.

From the outside, they appear identical.

Yet their experiences may be very different.

One person may enjoy socialising but become distracted by multiple conversations, struggle to regulate attention, interrupt others impulsively and leave feeling mentally exhausted.

Another person may find the social rules themselves difficult to interpret, feel uncertain about what is expected, become overwhelmed by noise and unpredictability, and require significant recovery time afterwards.

Both may avoid parties, and social gatherings of different types.

The reasons, however, are quite different.

This distinction matters because diagnosis is based upon understanding the underlying developmental pattern rather than simply counting similar-looking behaviours.

Some Differences Between ADHD and Autism

Although every individual is unique, there are some patterns that clinicians commonly explore:

Attention and Interests

People with ADHD often describe difficulty regulating attention.

Tasks that are repetitive, administrative or insufficiently stimulating may feel almost impossible to engage with, while highly interesting activities can become intensely absorbing.

Autistic people may also become deeply absorbed in subjects that interest them, but this often reflects enduring, highly focused interests rather than fluctuating attention.

Organisation and Routine

People with ADHD frequently struggle to establish routines despite wanting them.

They may intend to be organised but find themselves forgetting appointments, misplacing belongings or underestimating time.

Many autistic people, in contrast, find routines comforting and important. Unexpected changes can feel genuinely distressing because predictability reduces uncertainty and cognitive load.

Of course, someone with both conditions may simultaneously crave routine and struggle to maintain it.

Social Communication

Many people with ADHD enjoy social interaction but find themselves interrupting, speaking impulsively, forgetting details or moving rapidly between topics.

Autistic people may experience additional differences in understanding unwritten social conventions, interpreting non-literal language, recognising subtle social cues or intuitively knowing how conversations are expected to flow.

It is important to remember that these are broad tendencies rather than rules. Every autistic person communicates differently.

Sensory Experiences

Both ADHD and Autism can involve sensory sensitivities.

Someone may find bright lights, certain fabrics, background noise or crowded environments uncomfortable.

Sensory differences alone therefore do not distinguish between the two conditions, but they contribute to the overall clinical picture.

Can You Have Both ADHD and Autism?

Yes.

In fact, it is increasingly recognised that many people meet the diagnostic criteria for both conditions.

For years, diagnostic systems did not allow clinicians to diagnose both ADHD and Autism together. We now know that they commonly co-occur.

When someone has both conditions, they may experience an interesting combination of strengths and challenges, and each presentation tends to be quite unique.

For example, they may value structure and predictability while simultaneously finding it extremely difficult to create or maintain routines.

They may enjoy spending time with others but also find social situations exhausting.

They may seek novelty while also becoming overwhelmed by change.

Rather than cancelling one another out, the two conditions can create a unique pattern that deserves careful exploration.

Could it be something else?  –  Differential diagnostic considerations.

Another important consideration is that ADHD and Autism are not the only explanations for difficulties with concentration, emotional regulation or relationships.

For example:

• Anxiety;
• Depression;
• Trauma;
• Sleep difficulties;
• Obsessive-compulsive disorder;
• Learning differences;
• Physical health conditions;
• Chronic stress or burnout,

can all influence attention, memory, emotional wellbeing and everyday functioning.

Sometimes these conditions occur alongside ADHD or Autism.

Sometimes they provide a more accurate explanation.

This is one reason why a comprehensive assessment is invaluable, and also why it takes time, and cannot be rushed.  It is essential to take as long as it needs to take.

A diagnosis should never be made simply because someone recognises themselves in a list of symptoms.  Interestingly, most people can relate on some level to some symptoms of both ADHD and autism, just not to the level that justifies a diagnosis.

This is the same as most people feeling down at some point, but only some people are clinically depressed.

So which assessment should you choose?

This is one of the most common questions we are asked.

Sometimes the answer is straightforward.

For example, someone may present with a developmental history and current presentation that strongly suggests ADHD with relatively little evidence of Autism.

Equally, someone else may demonstrate a profile that is much more consistent with Autism.

However, there are many people whose experiences overlap considerably.

In these situations, attempting to decide alone can feel overwhelming.

This is why an initial screening appointment can often be helpful.  At Clear Sky Therapies, we always consider both conditions, as well as other mental, physical and historical factors.

Rather than assuming one diagnosis from the outset, screening allows us to explore your developmental history, current experiences and areas of difficulty before considering which assessment is likely to provide the most appropriate and clinically meaningful answer.

For some individuals, this indicates that a single assessment is appropriate.

For others, it suggests that assessment for both conditions should be considered.

Why a Comprehensive Assessment Matters

Whether you are assessed for ADHD, Autism or both, the purpose of the assessment should not simply be to decide whether you receive a diagnosis.  ADHD assessment, and Autism assessments, need to be comprehensive.

A high-quality assessment seeks to understand your individual pattern of strengths, challenges and life experiences.

This includes considering:

• Your developmental history;
• Education and employment;
• Relationships;
• Executive functioning;
• Sensory experiences;
• Emotional wellbeing;
• Coping strategies;
• Information from people who know you well;
• and alternative explanations for your difficulties.

The aim is not to confirm what anyone already believes, but to arrive at the most accurate understanding possible.

You don’t have to work this out alone

Many people spend months, or even years, wondering whether ADHD, Autism or both best explains their experiences.

You do not need to have the answer before seeking professional advice.

In fact, part of the clinician’s role is to help answer that question with you.

The goal is not simply to apply a diagnostic label.

It is to understand how your brain works, recognise both your strengths and the difficulties you experience, and provide clear recommendations that help you move forward with greater confidence and self-understanding.

Frequently Asked Questions

Can I have ADHD without being autistic?

Yes. Many people meet the diagnostic criteria for ADHD without meeting the criteria for Autism.

Can I be autistic without having ADHD?

Absolutely. Although the conditions frequently co-occur, many autistic people do not have ADHD.

Is one assessment enough?

Sometimes. If your presentation clearly suggests one condition, a single assessment may be appropriate. If there is significant overlap, it may be helpful to discuss whether assessment for both conditions would provide a more complete understanding.

What if I am unsure?

You do not need to decide on your own. An initial screening appointment can help identify which assessment is most appropriate based on your developmental history, current experiences and the difficulties you would like to understand.