Early signs of autism and ADHD in children and teens: What to look for
Signs of autism and ADHD in children will often appear before the age of 12, but no two children will experience or express them in the same way. Some behaviours and symptoms are easy to spot, while others may be more subtle, especially if a child is masking their traits to fit in.
As a parent or caregiver, recognising these early signs can make a real difference. Understanding what’s typical and what might need a closer look, is the first step to getting the right support. A formal diagnosis can open doors to tailored therapies, school support, and coping strategies that help your child thrive — at home, in the classroom, and beyond.
Research shows that children and teens diagnosed early benefit from targeted support that builds confidence, strengthens emotional wellbeing, and supports both social and academic development.
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Common signs of autism and ADHD in children and teens
In the UK, it’s estimated that around 5% of children have ADHD. ADHD can affect children in various ways, influencing their behaviour, emotions and ability to focus. Symptoms may vary for each child, but common traits include:
Inattention
Children with ADHD may struggle to maintain focus on tasks, frequently getting distracted or forgetting instructions. They may find it difficult to complete schoolwork or follow through with tasks, leading to frustration. These behaviours can lead family members and educators to misunderstand their condition, believing them to be lazy or distracted.
Elizabeth Broadbent, a parent of three children with ADHD explains: “Kids with inattentive ADHD don’t consciously choose what grabs their attention. So, while Blaise’s hyperfocused research into cryptozoology has him beating adults in trivia contests, he often forgets dinner because he’s programming Roblox.”
Elizabeth Broadbent, Mother to three sons with ADHD
Hyperactivity and impulsivity
Many children with ADHD display excessive energy, constantly moving or fidgeting, even in situations where they are expected to be still. Impulsivity may lead to interrupting conversations, difficulty waiting their turn or acting without considering consequences. While this sub type is thought to affect 15% of children with ADHD, it can cause challenges in the classroom without the right support in place.
Executive function challenges
ADHD can impact a child or teen’s ability to plan ahead, organise and manage time effectively. They may forget assignments, struggle with routines or find it challenging to complete multi-step tasks.
“In many people with ADHD, executive function doesn’t work as it should because the parts of the brain that control these skills are impacted by ADHD. And that affects everyday actions like making decisions, adapting behaviour in response to a changing environment and navigating relationship dynamics.”
Peg Dawson, Ed.D., member of the ADDitude ADHD Medical Review Panel
Common signs of autism in children and teens
Approximately 1 in 100 children are diagnosed with autism. Autism affects children differently, with some displaying noticeable traits early on, while others may consciously or unconsciously mask their symptoms to fit in with their peers. This can mean their autism can go undiagnosed and can be more difficult to make genuine connections. The additional effort required to hide their autistic behaviours can lead to burnout or mental health issues.
While autism exists across a spectrum, common characteristics include:
Social communication differences
Children with autism might find it hard to read social cues, make eye contact, or keep a conversation going. They may prefer playing on their own or feel unsure about how to join in with others. It’s common for children with autism to experience a delay in language development and it’s estimated that around 30% of people with autism might not speak at all, temporarily, or only in certain situations going into adulthood.
Need for routine and repetitive behaviours
A strong preference for routine and predictability is common in children with autism. Changes in schedules or disruptions to familiar environments can cause distress and repetitive movements or behaviours may provide comfort.
“My mind was constantly whirring with thoughts, worries and concerns. The time spent with my intense interest was the only time in which I had a clear mind – it gave me that much sought-after relaxation.”
Young person with autism, National Autistic Society
Sensory sensitivities
Many individuals with autism experience differences in how they process sensory input, which can impact their daily lives. Around 9 in 10 people with autism have heightened or reduced sensitivity to sights, sounds, smells, tastes, touch, balance or body awareness. Loud noises, bright lights, certain textures, or strong smells may feel overwhelming, leading to avoidance or distress in specific environments.
These sensory differences influence how a child or teen may feel physically, where they feel comfortable going and how they interact with others. Some may be over-sensitive, finding certain sensations intense or uncomfortable, while others may be under-sensitive, making it harder to notice or respond to sensory input. Many children may experience a mix of both.
How to tell the difference between ADHD and autism
ADHD and autism share some overlapping traits, such as challenges with focus, impulsivity and sensory sensitivities, but they remain distinct conditions. ADHD is primarily linked to difficulties with attention regulation and impulse control, whereas autism is associated with differences in communication, social interaction and a preference for routine. Some individuals have both ADHD and autism, meaning their needs span characteristics of both conditions.
ADHD and autism combined: When diagnoses overlap
Some children are diagnosed with both ADHD and autism, a combination often referred to as a dual diagnosis. You might also hear the term “AuDHD”, which is becoming more common within the neurodivergent community to describe people who experience traits of both conditions.
While ADHD and autism are different, they can share certain challenges, such as difficulties with focus, managing emotions, sensory sensitivities, or navigating social situations. At the same time, each condition has its own distinct characteristics. ADHD is typically linked to challenges with attention, hyperactivity, and impulse control, while autism is often associated with differences in communication, social interaction, and a strong need for routine or predictability.
When both conditions occur together, children may face a unique mix of strengths and struggles – for example, wanting things to stay the same (an autistic trait) while also finding it hard to plan or stay on task (an ADHD trait). This can sometimes create internal conflict or confusion, especially without the right support in place.
Recent research suggests that:
Around 1 in 5 children with ADHD also meet the criteria for autism
Around 1 in 4 autistic children also meet the criteria for ADHD
Recognising both conditions early on can help parents, teachers, and professionals provide tailored support that meets the child’s full range of needs.
When to seek support
Recognising early signs of ADHD or autism in children and teens can make a meaningful difference in their development. Seeking professional guidance allows families and educators to better understand a young person’s unique strengths and challenges, leading to tailored support through therapy, classroom adjustments, medication or structured routines. Early intervention helps children and teenagers thrive by building confidence, independence, and emotional wellbeing.
A formal assessment provides access to essential resources, such as speech and occupational therapy, which support a child’s ability to adapt and grow. By addressing these challenges early, you can create a nurturing environment that maximises your child’s potential and quality of life.
If you’re noticing signs of autism or ADHD in your child or teen, early support can make a world of difference. At Xyla, we offer comprehensive assessments and personalised guidance to help your child thrive.
With Xyla, you don’t need to wait months for answers. Early intervention empowers your child to thrive socially, emotionally and academically.
Not sure where to start?
We offer a free phone consultation to answer any initial questions. We’ll listen, understand your needs and guide you toward the right assessment or support. There’s no obligation, just reassurance and a helpful conversation.
Book a free consultationReferences
- National Autistic Society. (n.d.). What is autism? Retrieved from https://www.autism.org.uk
- ADDitude. (2023). Executive function challenges in ADHD. Retrieved from https://www.additudemag.com
- Dawson, P. (2020). ADHD and executive function: A neurodevelopmental approach. ADDitude.
- Broadbent, E. (2023). Parent perspective on ADHD and hyperfocus. Personal interview.
- National Institute of Mental Health. (2021). Attention-Deficit/Hyperactivity Disorder. Retrieved from https://www.nimh.nih.gov
- American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Arlington, VA: American Psychiatric Publishing.
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