AuDHD vs ADHD: How to Tell the Difference

Written by Dr. Simon Khela MBChB MRCGP, GMC Registered Doctor

Last reviewed: 20-07-2026

_________________________________________________________________________

A patient in his thirties came to see me last year after his daughter was diagnosed with autism. Reading through her assessment report, he told me it felt uncomfortably like reading about himself, except he’d been diagnosed with ADHD a decade earlier and had never once considered that autism might be part of his picture too. He’d spent years wondering why standard ADHD advice, structure, routines, fidget tools, never quite worked for him the way it seemed to for other people with the same diagnosis. It turned out he had both.

This is one of the most common patterns I see in adult neurodevelopmental assessments now, and it’s a large part of why the term AUDHD has spread so quickly, particularly online. It isn’t an official diagnostic label you’ll find in a medical textbook, but it describes something real: a growing recognition that ADHD and autism frequently occur together, and that the combination behaves differently from either condition alone.

This article sets out to explain, clearly and without hype, what AUDHD actually means, how it differs from ADHD on its own, what the overlapping and sometimes contradictory symptoms look like, and how diagnosis works in the UK.

What Is the Difference Between AUDHD and ADHD?

ADHD (Attention Deficit Hyperactivity Disorder) is a recognised neurodevelopmental condition affecting attention, impulse control and, in some people, hyperactivity. AUDHD is not a formal clinical diagnosis. It’s an informal term used to describe someone who has both ADHD and autism spectrum disorder at the same time, a combination that research suggests is common, with some studies estimating that a significant proportion of autistic people also meet the criteria for ADHD, and vice versa.

The key difference in practice is that ADHD alone tends to involve difficulty with attention regulation, impulsivity and, often, a need for stimulation and novelty. Autism alone tends to involve differences in social communication, a strong preference for routine and predictability, and sensory sensitivities. When both occur together, as in AUDHD, these traits can pull in opposite directions internally, for example, needing routine to feel calm (autism) while also finding routine boring and understimulating (ADHD), which is part of why people with both conditions often describe feeling unusually exhausted, contradictory, or hard to understand, even to themselves.

Diagnosis for both conditions in the UK typically involves a specialist assessment, either through the NHS or privately, and the two are assessed separately, even when someone is being evaluated for both at the same time.

What Is ADHD?

ADHD is a neurodevelopmental condition, meaning it relates to differences in brain development and function, typically present from childhood, though it’s increasingly recognised and diagnosed in adults who were missed earlier in life. It affects the brain’s executive function systems, which govern attention regulation, impulse control, working memory, and, in some presentations, physical restlessness.

There are three recognised presentations:

• Inattentive presentation – difficulty sustaining attention, disorganisation, forgetfulness, losing things, being easily distracted
• Hyperactive-impulsive presentation – restlessness, impulsivity, interrupting others, difficulty waiting or sitting still
• Combined presentation – a mix of both, which is the most commonly diagnosed type

Many patients are surprised to learn that ADHD doesn’t always look like the stereotype of a hyperactive child bouncing off the walls. In adults, particularly women, it often presents as chronic disorganisation, emotional dysregulation, procrastination despite genuine effort, and a persistent sense of underachieving relative to one’s actual ability, something ADHD UK and the NHS both describe as commonly overlooked presentations.

ADHD Symptoms

Core symptoms in adults

• Difficulty sustaining focus, particularly on tasks that aren’t inherently interesting
• Losing track of time, appointments, or deadlines
• Impulsive decisions, including financial, social or occupational choices made without full consideration
• Restlessness; ADHD in adults is often internal (a racing mind) rather than visibly physical
• Difficulty completing tasks once the initial interest has worn off
• Emotional reactivity, feeling emotions more intensely and finding it harder to regulate frustration or disappointment
• Hyperfocus, an intense, sometimes many-hours-long absorption in a task of genuine interest, which many people don’t realise is also part of the ADHD picture, not just the inattentive side

Symptoms in children

• Difficulty staying seated or waiting their turn
• Frequently interrupting or blurting out answers
• Losing school equipment or forgetting instructions
• Appearing not to listen when spoken to directly
• Excessive talking or physical restlessness

A question I’m frequently asked is why some children seem to “grow out of” ADHD. In reality, the hyperactive component often does become less visible with age, but the attention and impulse-control difficulties frequently persist into adulthood in a less physically obvious form, which is one reason ADHD in adults is so often missed until much later in life, sometimes only after a child’s own diagnosis prompts a parent to reflect on their own history.

What Is AUDHD?

AUDHD describes the co-occurrence of ADHD and autism spectrum disorder in the same person. Autism itself is a neurodevelopmental condition affecting social communication, sensory processing, and behaviour, typically involving a strong preference for routine, predictability and specific interests, along with differences in how social interaction is experienced and processed.

Historically, UK diagnostic practice for many years discouraged diagnosing both conditions in the same person, partly due to older diagnostic criteria that treated them as mutually exclusive. This has since changed, and current NHS and NICE-informed practice recognises that the two conditions frequently co-occur, with research consistently showing meaningful overlap between autistic and ADHD populations.

What makes AUDHD clinically distinct isn’t simply “autism and ADHD symptoms added together”. The two conditions interact, sometimes masking each other, sometimes amplifying each other, in ways that can make the presentation harder to recognise than either condition alone.

AUDHD Symptoms

Many patients describe AUDHD as feeling like being pulled in two directions simultaneously. Some of the patterns I see most often include:

• Needing routine, but also craving novelty. The autistic need for predictability sits alongside the ADHD need for stimulation, which can create genuine internal conflict, not simply indecision.
• Sensory sensitivity combined with impulsive sensory-seeking. Someone might be highly sensitive to certain textures, sounds or lighting, while also fidgeting, seeking movement, or craving certain physical sensations.
• Masking that becomes exhausting. Autistic masking (consciously suppressing natural behaviours to appear more socially typical) combined with the impulsivity of ADHD often leads to significant mental fatigue, sometimes described as autistic burnout, particularly in adults diagnosed later in life.
• Social difficulties that look different from “classic” autism. ADHD impulsivity, such as interrupting or oversharing, can mask or be mistaken for the social communication differences of autism, and vice versa, which is part of why co-occurring presentations are so often missed in earlier assessments.
• Emotional dysregulation from both directions. ADHD-related emotional reactivity combined with autism-related difficulty processing or communicating internal emotional states can result in intense emotional experiences that are hard to identify or explain to others.
• Executive function difficulties amplified rather than simply added together. Organisation, planning and task initiation, already affected by ADHD, can be further complicated by autistic traits such as difficulty shifting between tasks or tolerating unexpected change.

One of the most common concerns I see in practice is a patient who was diagnosed with ADHD years earlier, treated with standard ADHD strategies or medication, and found some but not full improvement, only to later recognise autistic traits that explain the parts of their experience that ADHD alone never quite accounted for.

ADHD vs AUDHD: Comparison Table

‍

ADHD Test and AUDHD Test: What Actually Counts as Testing?

There’s no single blood test, brain scan or definitive laboratory test for either ADHD or autism. Diagnosis is based on a detailed clinical assessment, developmental history, and standardised diagnostic tools, carried out by a suitably qualified specialist.

For ADHD, this typically involves structured interviews and validated screening tools such as the Adult ADHD Self-Report Scale (ASRS), alongside a detailed history covering childhood behaviour, current functioning, and impact across multiple areas of life (work, relationships, daily functioning). A diagnosis isn’t made from a screening tool score alone. These tools flag the likelihood of ADHD and guide further assessment; they don’t replace a full clinical evaluation.

For autism, assessment usually includes structured diagnostic interviews such as the ADOS-2 or ADI-R, developmental history (including input from parents or family members where possible, particularly regarding childhood), and observation of social communication and behaviour.

Many patients search for an “ADHD test” or “AUDHD test” expecting something quick and definitive online. Free online questionnaires, including the ASRS or the Autism Spectrum Quotient (AQ-10), can be a genuinely useful starting point for deciding whether to seek a full assessment, and I’d encourage anyone who recognises a lot of themselves in this article to try one. But they are screening tools, not diagnoses, and a high score means “worth getting assessed properly”, not “you definitely have this condition”.

ADHD Diagnosis and AUDHD Diagnosis: How It Works in the UK

Diagnosis for both conditions in the UK can be pursued via the NHS or privately, and the practical realities of each pathway differ considerably.

On the NHS, adult ADHD and autism assessment waiting lists have grown substantially in recent years. In many parts of the UK, current waiting times for an adult ADHD assessment can extend to several years, and autism assessment waiting lists are often similarly lengthy, a situation acknowledged publicly by NHS England and reflected in NICE guidance on ADHD, which recommends timely assessment but doesn’t control local service capacity.

Private assessment is considerably faster in most cases, typically weeks rather than years, though it comes at a cost that isn’t accessible to everyone, and it’s worth confirming that any private provider is appropriately regulated and that clinicians hold relevant specialist qualifications, since assessment quality varies between providers.

For someone being assessed for both conditions, most UK services, NHS and private, now assess them separately using condition-specific tools, sometimes within the same overall appointment structure, but the diagnostic criteria and process for autism and ADHD remain distinct even when co-occurring.

If a diagnosis is confirmed, specialist referrals and follow-up care, including consideration of ADHD medication where appropriate, ongoing psychological support, or workplace and educational adjustments, typically follow, guided by the specifics of the individual’s presentation rather than a one-size-fits-all treatment plan.

Common Myths and Misconceptions

“AUDHD is a new, made-up diagnosis.”

AUDHD isn’t a formal clinical diagnosis, but the co-occurrence it describes, ADHD and autism together, is a well-recognised and increasingly studied clinical reality, not a social media invention.

“You can’t have both ADHD and autism.”

This was a widely held view under older diagnostic frameworks, but current understanding recognises significant overlap, and many people are formally diagnosed with both conditions.

“If you’re diagnosed with ADHD, autism doesn’t need to be considered.”

Many patients are surprised to learn the opposite is often true. Recognising ADHD sometimes opens the door to identifying autistic traits that were previously masked, misattributed, or simply not considered.

“AUDHD always looks like a more severe version of either condition.”

Not necessarily. The combination often produces a distinct, sometimes contradictory pattern of traits rather than simply “more” of either condition.

“An online quiz can confirm you have ADHD or autism.”

Screening tools can indicate whether further assessment is worthwhile, but a proper diagnosis requires a full specialist evaluation, not a quiz result alone.

Benefits and Limitations of Seeking a Diagnosis

Understanding whether ADHD, autism, or both are contributing to someone’s experience can be genuinely clarifying. Many patients describe a sense of relief at finally having an explanation for lifelong patterns they’d previously attributed to personal failing, laziness, or simply “being difficult”. A formal diagnosis can also open access to reasonable adjustments at work or in education, appropriate treatment options, and more targeted psychological support.

That said, diagnosis isn’t a complete solution on its own, and it’s worth being realistic about this. Long NHS waiting times mean many people wait a considerable time for confirmation. Private assessment, while faster, isn’t affordable for everyone. And a diagnosis doesn’t automatically resolve day-to-day challenges. It provides a framework for understanding and accessing appropriate support, but ongoing strategies, and sometimes medication or therapy, are usually still needed alongside it.

When Should You Consider Assessment?

I’d generally suggest considering a proper assessment if you recognise a consistent, longstanding pattern (not just occasional experiences) of:

• Persistent difficulty with attention, organisation or impulse control that has affected work, relationships or daily functioning since childhood
• A strong need for routine alongside a conflicting need for novelty or stimulation
• Sensory sensitivities alongside impulsivity or sensory-seeking behaviour
• Longstanding social difficulties that don’t fit neatly into either an ADHD or autism picture alone
• Significant exhaustion from “keeping up appearances” socially, sometimes followed by burnout or withdrawal

A private GP appointment you can also opt for: online GP consultation, which is a reasonable first step if you’re unsure which pathway is right for you, since a GP can discuss your history, rule out overlapping explanations, and guide an appropriate referral, whether that’s for an ADHD assessment, an autism assessment, or both.

specialist, because an accurate diagnosis is what actually opens the door to support that helps.

Frequently Asked Questions