If you have spent months quietly trying to work out whether your child’s difficulties look more like ADHD or more like autism, you are not being indecisive. The two frequently sit side by side. Many young people show clear traits of both, and the boundary between them is far blurrier than most parents expect. Understanding how they overlap can make daily life feel less confusing, and it can help you find support that actually fits your family.
Research points to shared genetic heritability between autism spectrum disorder (ASD) and ADHD, along with shared difficulties in social functioning and executive function. In plain terms, the same underlying biology can shape development in ways that show up across both areas at once.
Co-occurrence is common rather than unusual. One ADHD information source notes that more than half of people diagnosed with ASD also show signs of ADHD, describing ADHD as the most common coexisting condition in children. Autistica, a UK autism charity, puts it simply: the two frequently co-occur, and many people with one diagnosis show elevated traits of the other.
Individually, a 2024 review reports prevalence of around 5 per cent for ADHD and around 1 per cent for ASD. Once you look at people already being assessed, the overlap rises sharply. One review found that 22 per cent of those with suspected ADHD met the criteria for ASD. Another overview of the topic states that around a third of people with ADHD also had autism. This is why the term AuDHD has become so familiar to families.
Definitions and current guidance do change over time, so it is always worth checking official NHS and charity sources for the most up to date information.
When you read through the list below, more that one experience. That is normal, and it does not mean you are imagining things or reading too much into them.
ADHD is generally defined by a persistent pattern of inattention and/or hyperactivity and impulsivity that interferes with day to day functioning or development. Autism influences how a person experiences and interacts with the world, and NHS information describes it as a lifelong neurodivergence and disability, characterised by differences in social communication alongside repetitive patterns.
A useful shorthand is this: ADHD tends to show up in how a young person directs and regulates attention and impulses, while autism tends to show up in how they experience sensory input, social connection, and routine. Someone with ADHD may actively seek out novelty, while autistic young people often find comfort in sameness. Most real teenagers are doing a bit of both, and the picture shifts with tiredness, stress, and where they are in the school term.
When both are present, research suggests functioning can be harder. A 2024 review found that people with co-occurring ASD and ADHD showed greater difficulty with communication, social skills, and adaptability. That is not a prediction about your child. It is a reason to take overlapping traits seriously and to put support in place early.
Early adolescence is often when overlapping traits become impossible to ignore. Primary school can be forgiving of a child who is bright but scattered, or quiet but intense. Secondary school is less so. Timetables change, friendship groups shift, homework piles up, and the sensory load of corridors and canteens is relentless.
Between 11 and 16, you might notice a young person who is wiped out by 4pm, who can rehearse a conversation for an hour afterwards, who cannot start an essay but can talk for two hours about a special interest. Revision and exams add pressure, because they demand exactly the skills that tend to be hardest: planning, sustaining attention, tolerating boredom, and staying calm in a room full of people.
From 16 to 25 the demands change shape rather than ease. College and university bring less structure and more independence. Work brings new social rules. Managing money, appointments, and laundry all lean on executive function. Many families find that the same young person who coped surprisingly well at school hits a wall in their first year of independence, not because they have got worse, but because the scaffolding has gone.
Families often arrive at this topic through a label, or through the absence of one. Waiting lists, differing opinions between professionals, and the language used in reports can leave parents feeling that nothing counts until a diagnosis is confirmed.
In practice, the support that helps is built around traits, not titles. If your child struggles to start tasks, you can work on that. If they are floored by noise, you can plan around it. If rejection stings for days, you can name it and practise responses together. These strategies work whether or not a formal label ever arrives, and they do not require you to decide which condition fits best.
It also helps to keep the tone neutral at home. Traits are not character flaws, and they are not something to be argued out of. Many young people describe their differences as part of who they are rather than a defect, and autism in particular is understood as a lifelong neurodivergence. Speaking about it that way protects self-esteem at an age when self-esteem is fragile.
There is a point where patience and good intentions are not enough on their own. If your child is avoiding school or college, withdrawing from friends, sleeping badly most nights, or their daily functioning is slipping, that is a signal to widen the circle of support.
Practical, non-diagnostic help can sit alongside whatever else you are arranging. Behavioural health coaching is one option. It is not a diagnosis and not a treatment for a clinical condition, but it offers structured, one-to-one support with the everyday skills that overlapping traits make difficult.
Synapse provides behavioural health coaching for young people aged 11 to 25 across the UK, delivered by trained coaches working under a clinically supervised multidisciplinary team. First call to active support happens within 7 days, and the focus stays on coping in daily life rather than on labels.
If you are unsure whether coaching is the right fit, or whether something more urgent is going on, ask. A short conversation can point you in the right direction, and you do not need to have everything worked out before you get in touch.
Can someone have both ADHD and autism?
Yes. ADHD and autism frequently co-occur, and many people with one diagnosis show elevated traits of the other. One ADHD information source notes that more than half of people diagnosed with autism also show signs of ADHD, and describes ADHD as the most common coexisting condition in children. Some families and young people use the term AuDHD to describe this overlap.
How can I tell which one my child has?
Often you cannot, and you do not need to. The two conditions share genetic heritability and shared difficulties with social functioning and executive function, so traits blur. A pattern that looks like one at home may look like the other at school. Formal assessment belongs with qualified clinicians. At home, focus on the traits you can actually see and support.
Does having both make life harder?
Research suggests it can. A 2024 review found that people with co-occurring autism and ADHD showed more difficulty with communication, social skills, and adaptability. That does not mean your child is destined to struggle. It means support needs to cover more than one area, and that recognition and practical strategies early on can make a real difference.
Is coaching a replacement for diagnosis or therapy?
No. Behavioural health coaching is practical, non-diagnostic support. It helps young people build coping skills for everyday difficulties, and it is not a substitute for formal assessment or clinical treatment. At Synapse, coaching for 11 to 25 year olds is delivered by trained coaches working under a clinically supervised multidisciplinary team, so concerns can be escalated when they need to be.
