If you are thinking about getting assessed for neurodiversity – for yourself or your child – one of the first questions that often comes up is which kind of assessment is actually needed. Is it ADHD? Is it autism? Could it be both? And what is the difference between the two assessments anyway?
These are entirely reasonable questions, and the fact that they come up so often reflects something genuinely confusing about how ADHD and autism are discussed, diagnosed and understood. This guide aims to untangle some of that confusion.
ADHD and autism are different conditions – but they often overlap
ADHD (attention deficit hyperactivity disorder) and autism are both neurodevelopmental conditions, meaning they relate to how the brain develops and processes information. But they are distinct from each other, and the way they show up in everyday life can look quite different.
ADHD is primarily understood as a condition affecting executive function – the brain’s ability to plan, prioritise, regulate attention, manage time and control impulses. People with ADHD often describe a mind that is difficult to direct: easily distracted by things that are interesting, and equally difficult to get started on things that are not. Emotional regulation difficulties and a complicated relationship with time are also common features.
Autism is a neurodevelopmental condition characterised by differences in social communication and interaction, alongside restricted or repetitive patterns of behaviour, interests or sensory responses. Autistic people often describe a world that does not match their expectations – one where unwritten social rules feel opaque, where sensory input can be overwhelming, and where deep focus on specific interests brings genuine joy.
The reason this gets complicated is that ADHD and autism frequently co-occur. Research suggests that somewhere between 50 and 70 per cent of autistic people also have ADHD, and many people with ADHD also meet the criteria for an autism diagnosis. This means that for a significant proportion of people seeking assessment, the question is not ADHD or autism – it is ADHD and/or autism.
What does an ADHD assessment involve?
An ADHD assessment looks at a range of areas related to attention, executive function, impulsivity, hyperactivity and emotional regulation. It typically involves:
- Detailed questionnaires completed by the individual and, where appropriate, a parent, partner or teacher
- A structured clinical interview covering developmental history, current difficulties and the impact on daily life
- Standardised rating scales and cognitive screening tools
- A review of any previous reports, school records or medical history
For children, it is common to gather information from school as well as from parents. For adults, the assessment looks closely at how difficulties have shown up across the lifespan – including childhood, even if no formal concerns were raised at the time.
What does an autism assessment involve?
An autism assessment is typically more comprehensive than an ADHD assessment in terms of the number of structured tools used. It involves:
- Detailed developmental history – often gathered from a parent or carer as well as the individual
- Structured clinical interviews specifically designed for autism assessment, such as the ADOS-2 (Autism Diagnostic Observation Schedule) and ADI-R (Autism Diagnostic Interview – Revised)
- Questionnaires covering social communication, sensory experiences and repetitive behaviours
- Observation of communication and interaction styles
- Screening for co-occurring conditions including ADHD, anxiety and learning differences
Because autism exists on a wide spectrum and presents very differently in different people – particularly in women, girls and people who have masked their traits over many years – a thorough autism assessment takes time and requires a clinician who understands the full range of presentations.
How do I know which assessment I need?
The honest answer is that you do not always need to know before you begin. A good starting point is to describe your concerns to a specialist and let them guide the process. In many cases, a combined assessment – looking at both ADHD and autism – makes the most clinical sense, particularly if there are traits that could point to either or both.
Some indicators that ADHD might be the primary concern include: difficulty sustaining attention across most tasks, chronic disorganisation, time blindness, impulsive decision-making and emotional dysregulation that has been present since childhood.
Some indicators that autism might be worth exploring include: difficulty reading social cues or unwritten rules, strong sensory sensitivities, a preference for routine and predictability, deep focus on specific interests, and a persistent sense of being different from others in social situations – even when managing well on the surface.
Many people find that both sets of indicators resonate. If that is the case, a combined assessment is worth discussing.
Can I be assessed for both at the same time?
Yes. At Neuropathways Clinic we regularly carry out combined ADHD and autism assessments. This is often more efficient and more clinically complete than assessing for one and then the other, and it avoids the situation where an ADHD diagnosis is made without exploring whether autism might also be present – or vice versa.
A combined assessment produces a single comprehensive report covering both conditions, any co-occurring learning differences, and clear recommendations for next steps.
What if the assessment does not lead to a diagnosis?
A neurodiversity assessment is not simply about whether a diagnosis is given. It is about understanding. Some people go through an assessment and receive a formal diagnosis. Others do not meet the full criteria for a diagnosis but gain valuable insight into how their brain works and what kinds of support might help.
Either outcome is a useful one. The point of assessment is not to label – it is to understand, and to give the person the information they need to move forward with confidence.
At Neuropathways Clinic we offer ADHD assessments, autism assessments and combined assessments for people of all ages. If you are not sure where to start, a free discovery call with our team is the best first step. Book here, or call 0330 202 0283.
