If you are reading this, you have probably spent a long time watching your child closely and wondering if they may have autism or ADHD. Many parents start by thinking about one and then find themselves wondering whether both might apply. That instinct is worth listening to because recognising the signs that your child may need a combined autism and ADHD assessment can help you make sense of what you are seeing and decide whether a single-condition assessment is enough or whether the fuller picture only comes into focus when both conditions are considered together.
This guide explains what to look for, how autism and ADHD overlap, what the term AuDHD means, and when a combined assessment might be the right next step. It is here to help you make sense of things, not to diagnose. Only a qualified clinician can confirm whether your child is autistic, has ADHD, or both.
What Are the Signs Your Child May Need a Combined Assessment?
Your child may benefit from a combined assessment if they show traits linked to both autism and ADHD across more than one setting, such as home and school, and a single-condition explanation does not seem to account for the full picture. In other words, when one label does not quite fit.
Those traits can look very different depending on a child’s age, their gender, and how well they have learned to mask, meaning to cover up or compensate for their differences. A confident, chatty child can still be struggling underneath. The sections below break these signs down in more detail, so you can hold them up against what you see day to day.
Understanding the Difference Between Autism and ADHD
Autism and ADHD are distinct neurodevelopmental conditions, each with its own diagnostic criteria. Autism mainly involves differences in social communication and interaction, sensory processing, and a strong preference for routine and predictability. ADHD mainly involves differences in attention regulation, impulsivity, and, in some children, hyperactivity. In the UK, NHS services tend to use the ICD-11 criteria; the DSM-5 is also widely referenced, and the relevant NICE guidance is NG87 for ADHD and CG128 for autism.
Both are common. It is estimated that around 741,000 children and young people aged 5 to 24 in England have ADHD, including those who are not yet diagnosed.
One piece of history matters here. Until 2013, the DSM diagnostic criteria explicitly prevented a child from being diagnosed with both autism and ADHD at the same time. The DSM-5 removed that exclusion in 2013, so both conditions can now be recognised together when the criteria for each are met. If you have ever been told your child cannot have both, this is often why. If your child has already been seen for one condition, you may find Provide Wellbeing’s ADHD assessment for children and young people page a useful point of reference.
The Overlapping Traits That Make Diagnosis Complex
This is one of the most important things to understand. Autism and ADHD share several traits, which means it can be genuinely difficult to tell them apart or to spot that both are present at once. When both conditions are there, these shared traits often amplify each other.
Common areas of overlap include:
- Executive function difficulties: planning, organising, getting started on tasks, and keeping track of time
- Emotional dysregulation: intense emotional responses and difficulty settling once upset
- Difficulties with social interaction, though the underlying reason differs between the two conditions
- Hyperfocus and intense interests, where a child can become deeply absorbed in a topic or activity
- Sleep disturbances, which are common in both, and is often worse when both are present
- Sensory sensitivities, such as being over- or under-sensitive to sound, light, texture, or touch
- Rejection sensitivity: a heightened reaction to criticism or perceived exclusion
The social difficulties are worth singling out because they look similar on the surface but come from different places. In autism, social difficulties usually stem from differences in social understanding and communication style, for example, finding it hard to read unspoken social rules. In ADHD, they more often come from impulsivity, inattention, or emotional dysregulation, so a child may know what to do socially but struggle to do it in the moment. When both conditions are present, these two things interact and compound one another.
Masking adds another layer. Some children, and girls in particular, learn to hide their traits by copying expected behaviours, which can keep difficulties out of sight for years. Research has found that, on average, girls are diagnosed with autism around 1.8 years later than boys, with this gap reported in older studies and often widening when a child masks well. A child who copes at primary school can reach a point, often in secondary school, where the demands outgrow their coping strategies.
What Is AuDHD?
AuDHD is the term increasingly used by the neurodivergent community to describe co-occurring autism and ADHD. It is not a clinical diagnosis in its own right. It is a shorthand for the lived reality of having both conditions, and it is now widely used by parents, charities, and clinicians.
Co-occurrence is more common than many parents realise. Autistica reports that around 28% of autistic children meet the criteria for ADHD, and around 21% of children with ADHD are also autistic. Broader research puts the figure higher: a meta-analysis found the prevalence of ADHD in autistic people sat between 50% and 70%, so the numbers vary depending on how each study is set up. Either way, having both is far from unusual.
In daily life, AuDHD can create a particular pattern of difficulty that is different from either condition alone. There is often a tension between the autistic pull towards routine and predictability and the ADHD pull towards novelty and impulse. A child might insist on a set routine and then disrupt it themselves. They might want friendships but struggle both to read social rules and to manage their impulses in the moment. Executive function challenges are often more pronounced, and emotional regulation can be harder. Because one condition can mask the other, AuDHD is frequently missed, especially in girls and in children who have learned to mask.
When a Single Assessment May Not Give You the Full Picture
If your child has already been through an assessment for one condition and you are still left with unanswered questions, you may still not have the full picture.
A single assessment does not always capture everything. There are a few patterns that suggest the picture may be incomplete:
- Your child has an ADHD diagnosis, but still shows strong difficulties with social communication, sensory processing, or coping with change that the ADHD framework does not fully explain.
- Your child has an autism diagnosis, but still shows significant inattention, impulsivity, or hyperactivity that autism alone does not account for.
- Your child is awaiting an NHS assessment for one condition, and your concerns about the other have grown while you wait.
- Difficulties show up across more than one setting, such as both home and school, and across different types of challenges.
- Your child’s profile simply does not fit the classic presentation of the condition they were assessed for.
Waiting is a real part of the picture for many families. As of March 2025, around 224,000 people in England had an open referral for a suspected autism assessment, with 89.9% waiting longer than the 13-week guideline. When concerns about a second condition emerge during a long wait, it is worth raising both rather than starting the queue again from scratch.
Why a Combined Assessment Can Be Recommended
A combined assessment looks at autism and ADHD together within one pathway, rather than one after the other. There is a clear clinical reason for this. When the two conditions coexist, the traits of one can mask or change the way the other shows up. Assessing both at once lets clinicians see how the conditions interact, rather than viewing your child through a single lens and risking an incomplete picture.
There are practical reasons too. A combined assessment means you and your child do not have to repeat the same detailed developmental history across two separate processes, which many parents describe as draining. It also produces a single, joined-up report you can use for school support, EHCP applications, and onward referrals.
NICE guidance recognises that autism and ADHD frequently co-occur and supports multidisciplinary assessment that considers both. A clinician or GP may suggest a combined assessment when the referral information points to traits of both conditions, or when an initial screening raises questions across both areas. Gold-standard assessments typically draw on tools such as the ADOS-2 and ADI-R alongside ADHD-specific measures, delivered by a multidisciplinary team. Provide Wellbeing’s combined ADHD and autism assessment for children and young people aged 6 to 18 sets out exactly what that involves.
The Benefits of a Combined Assessment
For parents weighing up whether to pursue an assessment, it helps to see the benefits laid out clearly:
- A clearer, fuller understanding of your child’s strengths, needs, and the support that will actually help.
- One report instead of two, which reduces the paperwork burden on your family and your child’s school.
- No diagnostic overshadowing, where an ADHD diagnosis delays or hides an autism diagnosis, or the other way around.
- Recommendations that reflect both conditions together, which tend to be more accurate and more useful at home and in the classroom.
- Stronger evidence for an EHCP where both conditions are present.
That last point carries real weight. In 2024/25, autism was the primary need for 33.6% of the 483,000 pupils with an Education, Health and Care Plan in England, so a report that captures the full picture can make a real difference to the support a child receives. And even where a combined assessment does not confirm both conditions, it still gives you a more thorough picture than a single-condition assessment would on its own. A conclusion reached after both were properly considered carries more weight than one reached without looking.
What to Do Next If You Think Your Child May Need a Combined Assessment
If the signs in this article feel familiar, a good first step is to talk to your GP, who can advise on NHS referral pathways and what is available in your area. Depending on where you live, the NHS Right to Choose pathway may give you the option of an NHS-funded assessment with an alternative provider, and private combined assessments are also available for families who want to reduce waiting time. It can help to read up on the difference between NHS and private autism assessments before you decide.
There is no single right route, only the one that fits your family. If you would like to understand what an assessment involves, Provide Wellbeing offers neurodevelopmental assessments for children across Essex and East Anglia, backed by an established NHS provider.
Frequently Asked Questions
How Do I Tell if My Child Has Both ADHD and Autism?
Look for signs across both categories. If your child shows persistent difficulties with attention and impulsivity alongside differences in social communication, sensory processing, or flexibility, and these difficulties are present across more than one setting, it is worth raising both conditions with your GP or a specialist. Only a qualified clinician can confirm a diagnosis.
Can You Have a Combined Autism and ADHD Assessment?
Yes. A combined assessment looks at autism and ADHD within a single pathway, using standardised tools for both conditions. The outcome can confirm one condition, both, or neither, and either way, you come away with a more complete understanding of your child.
What Does Combined Autism and ADHD Look Like in a Child?
Children with both conditions may hyperfocus on a favourite interest while struggling to pay attention elsewhere. They may want social connection but find it hard to read social rules and to manage impulsive behaviour at the same time. Executive function and emotional regulation difficulties are often more pronounced than either condition alone would typically produce.
Is It Common for a Child to Have Both Autism and ADHD?
It is more common than many parents realise. Around 28% of autistic children meet the criteria for ADHD, and broader research puts the overlap higher still. Co-occurring diagnoses were historically under-recognised because the diagnostic criteria previously prevented both from being given at once, something that changed in 2013.
