ADHD vs autism is a common question among families, teachers and adults who notice differences in attention, behaviour or social interactions. ADHD is characterised by persistent patterns of inattention and/or hyperactivity-impulsivity that can affect everyday functioning. Autism involves differences in social communication and social interaction, alongside restricted or repetitive patterns of behaviour, interests or activities. These can include sensory differences and a preference for predictability. Both are neurodevelopmental conditions, and a person can have both.
In brief:
- ADHD affects how a person regulates attention, energy and impulses. Autism affects how a person communicates, processes sensory information and copes with change.
- The two conditions can look similar from the outside, even when the reasons behind a behaviour differ.
- Hyperfocus in ADHD and special interests in autism are not the same.
- Autistic people are more likely than average to also have ADHD, and the reverse is true.
- Only a qualified clinician can distinguish between the two conditions. Comparison tables like the ones below cannot be used to make a diagnosis.
This guide uses the term “autistic person” throughout, as many autistic people prefer this terminology. Others prefer “person with autism”, so it is worth asking which term a person prefers.
What Is the Difference Between ADHD and Autism?
ADHD mainly affects attention, activity levels, and impulse control. Autism mainly affects social communication, sensory processing,g and the need for routine and predictability. Both are neurodevelopmental conditions that begin in childhood, and some of their characteristics overlap. An assessment considers the whole picture rather than focusing on a single behaviour.
Because the two conditions can have similar characteristics, autism assessment and support should also take ADHD into consideration when appropriate. Both conditions are recognised in the DSM-5-TR, the current diagnostic manual, as neurodevelopmental conditions. ADHD has three presentations: predominantly inattentive, predominantly hyperactive-impulsive, and combined. Autism is described as a spectrum because the characteristics and level of support required vary from person to person.
ADHD vs Autism Symptoms: Side-by-Side Comparison
The table below outlines common differences between ADHD and autism, as well as areas where their characteristics overlap. These are general patterns rather than definitive rules. Every person is different, and the information cannot be used to diagnose either condition.
Area | ADHD | Autism | Often shared |
Attention | Attention shifts easily, and it can be difficult to sustain focus on tasks that hold little interest. | Attention may be intensely focused on preferred topics, while social cues may be overlooked. | Difficulty concentrating in noisy or busy environments |
Social interactions | May interrupt others, talk over them, or lose track of conversations | May find unspoken social rules, tone of voice or small talk difficult to interpret | Friendship difficulties and feeling misunderstood |
Communication | Speech may be fast, wandering or off-topic. | May interpret language literally, communicate differently through eye contact or tone, or prefer direct language. | Difficulty recognising hints or implied meanings |
Interests | Interests may change frequently, often driven by novelty. | Interests may be intense, detailed and long-lasting. | Strong enthusiasm for favourite topics |
Routine | May struggle to maintain routines while still benefiting from structure. | May rely on routines and find unexpected changes distressing. | Difficulty managing transitions |
Sensory processing | Sensory sensitivities may occur alongside restlessness. | Sensory differences are common and are a recognised feature of autism. | Distress caused by noise, textures or crowds |
Emotions | Emotional reactions may be quick and intense, sometimes settling relatively quickly. | Emotional or sensory overwhelm may build up and lead to a meltdown or shutdown. | Difficulty regulating emotions |
Movement | Fidgeting and restlessness may be common. | Repetitive movements, known as stimming, may help regulate or express feelings. | A need to move to cope with discomfort or maintain regulation |
Same Behaviour, Different Reasons
Two people can display the same behaviour for very different reasons. This is why assessors often explore why a behaviour occurs rather than focusing only on what it looks like.
Behaviour | Possible ADHD reason | Possible autism reason |
Avoiding groups | May become bored or distracted, or worry about blurting something out | May find group conversations tiring, unpredictable or too noisy |
Meltdowns | May experience an impulsive emotional reaction to frustration that settles relatively quickly | May experience sensory or emotional overload that has built up over time |
Not listening | May become distracted, or the instruction may not be retained in working memory | May not process the instruction or may be absorbed in another activity |
Interrupting | May worry about forgetting a thought or struggle to wait for a turn | May misinterpret conversational turn-taking or feel enthusiastic about a topic |
Fidgeting vs stimming | May release restless energy and help maintain focus | May help regulate emotions, provide comfort or express feelings, often through repeated movements |
Consider a child who struggles to line up with their class. One child may be too distracted to notice the line forming, while another may find the crowded, noisy environment physically uncomfortable. Although the behaviour looks similar, the support required may be very different.
Hyperfocus vs Special Interests: How They Differ
ADHD hyperfocus involves intense concentration on something stimulating or engaging, sometimes lasting for hours. Autistic special interests are often deep, long-lasting passions that may remain consistent for years. Both can be difficult to interrupt. One difference is how long an interest lasts and the role it plays in a person’s life.
ADHD hyperfocus may shift between new and exciting topics, while autistic special interests are often more consistent and long-lasting. For example, a teenager with ADHD might spend an entire weekend building a game before moving on to a new hobby the following month. An autistic teenager might develop an extensive knowledge of trains over many years and find joy and comfort in that interest.
Special interests can contribute to a person’s identity, comfort and sense of connection. Hyperfocus can be a strength, but it may also lead to missed meals, overlooked deadlines, or insufficient sleep.
Routine in Autism vs ADHD
Many autistic people rely on routines and find unexpected changes distressing. People with ADHD may also want routines but struggle to maintain them. The difference often lies in the purpose of the routine and how a person responds when it is disrupted.
For an autistic person, a predictable routine may reduce anxiety. A cancelled plan or a change to the timetable can cause significant distress. For someone with ADHD, a routine can provide external structure to support planning and memory. The main difficulty may be starting or maintaining the routine rather than coping with changes to it.
Both groups may find transitions difficult. An autistic child may resist leaving an activity because the change itself feels uncomfortable. A child with ADHD may resist the transition because the next task seems less interesting.
Sensory Issues in ADHD and Autism
Sensory differences are a recognised feature of autism, but they can also occur in ADHD. Sensory reactivity is included in the diagnostic criteria for autism. Although sensory difficulties are common in people with ADHD, they are not part of the core diagnostic criteria for ADHD and may contribute to distraction or feelings of overwhelm.
Sensory issues associated with ADHD or autism may include covering one’s ears in loud places, refusing certain clothing or foods, or struggling to concentrate when background noise is present. An occupational therapist can assess a person’s sensory needs and suggest practical strategies, regardless of their diagnosis.
Social Difficulties in ADHD and Autism
Social difficulties can occur in both conditions, although the underlying reasons may differ. In ADHD, impulsivity and inattention can disrupt conversations. In autism, difficulties may relate to interpreting unwritten social rules, tone of voice, and other people’s intentions.
A person with ADHD may interrupt because they are afraid of forgetting what they wanted to say. An autistic person may not realise when it is their turn to speak. Both may experience exclusion or feel hurt by social interactions. Support options, such as social skills groups, teacher awareness and clear communication, may help people with either condition.
Why ADHD and Autism Are Often Confused
ADHD and autism are often confused because they share several characteristics, including difficulties with executive functioning, emotional regulation, sensory processing and social interaction. Executive functioning refers to skills such as planning, organising, switching between tasks and holding information in mind.
Both conditions can involve:
- Difficulty planning, starting and finishing tasks
- Intense emotions that are difficult to regulate
- Sensitivity to sound, light or touch
- Awkward or misunderstood social interactions
A child who is off task in class might be daydreaming, overwhelmed by noise, or lost in thought. A teacher who observes this behaviour might suspect ADHD, while a parent who notices emotional outbursts at home might suspect autism. Overlapping characteristics can sometimes contribute to an initial misdiagnosis or lead to one condition being overlooked while the other is identified.
How Common Is the Overlap Between ADHD and Autism?
Overlap is common, but estimates vary considerably. A large 2019 meta-analysis found that ADHD was the most common co-occurring mental health condition among autistic people, with a prevalence of approximately 28%. A pooled analysis of studies involving children and adolescents with ADHD, conducted by Hollingdale and colleagues in 2020, found that approximately 21% also had autism.
Other reviews report a much wider range of estimates. An umbrella review of meta-analyses reported ADHD prevalence among autistic people ranging from 26% to 65%. These differences may be influenced by several factors:
- Sample type: Clinical samples, which include people seeking professional help, tend to show higher rates than community samples.
- Age: Rates can differ between children, teenagers and adults, and some characteristics may only be recognised later in life.
- Intellectual disability: ADHD may be more difficult to identify or may be classified differently in some studies.
- Diagnostic criteria: Older diagnostic manuals did not allow both conditions to be diagnosed together, and studies may use different assessment tools.
For these reasons, individual prevalence figures should be treated as estimates rather than fixed facts. Be cautious of claims about a 50–70% overlap when they are not supported by reliable sources.
People with both conditions may also experience anxiety. A 2022 study published in the Journal of Autism and Developmental Disorders reported high rates of anxiety among autistic teenagers who also had ADHD, at approximately 72% of females and 69% of males.
Can You Have Both ADHD and Autism?
Yes. Many people have both conditions. Before 2013, the DSM did not allow ADHD and autism to be diagnosed together, which meant that some cases of co-occurrence were not formally recognised. Under the DSM-5, clinicians can diagnose both conditions when the diagnostic criteria for each are met.
For more information, our guide to AuDHD signs and daily challenges explains what living with both conditions can look like.
ADHD vs Autism in Adults
In adults, the characteristics of both conditions may be masked by years of developing coping strategies. Some adults seek an assessment after their child receives a diagnosis, during a period of career-related stress or following burnout. They may begin to question why they have always felt different.
ADHD in adults may involve chronic disorganisation, missed deadlines, restlessness, impulsive decisions and difficulties with time management. Autism in adults may involve exhaustion after social interactions, a strong preference for routine, sensory overload at work and a need for time alone to recover.
At work, an adult with ADHD may thrive on variety but struggle with administrative tasks. An autistic adult may excel at detailed, focused work but find open-plan offices and unclear expectations draining.
An adult psychiatric assessment can explore your history, including your childhood experiences, to help determine whether ADHD, autism, or both may explain your difficulties. School reports, family observations and past experiences can also provide useful information.
ADHD vs Autism in Girls and Women
Girls and women are often diagnosed later in life, partly because their characteristics may be less noticeable or more effectively masked. Some learn to imitate social behaviours to fit in, a process known as masking, which can contribute to anxiety and exhaustion.
In girls, ADHD is more likely to present with inattentive symptoms than with obvious hyperactivity. As a result, they may be perceived as dreamy or shy rather than disruptive. Autistic girls may have strong language skills and one or two close friendships, which can make their difficulties less apparent. Anxiety, low mood and perfectionism may be noticed first, while the underlying condition remains unrecognised.
Many girls conceal their differences to fit in with others. Understanding why masking is so exhausting can help explain why ADHD or autism may go unrecognised in girls and women. Some women are not diagnosed until adulthood, sometimes after their child undergoes an assessment.
How ADHD and Autism Are Assessed in Australia
In Australia, ADHD and autism can be assessed by appropriately qualified clinicians, including paediatricians, psychiatrists and psychologists, depending on the condition and the clinician’s scope of practice. Speech pathologists and occupational therapists may also contribute relevant information. Assessments typically consider developmental history, current functioning,g and information from family members, schools,s or workplaces.
Clinicians consider both conditions because some of their characteristics overlap. The DSM did not permit a dual diagnosis of ADHD and autism until the DSM-5 was introduced in 2013. Both conditions can now be diagnosed together when the relevant criteria are met.
The Autism CRC national guideline provides guidance on autism assessment in Australia. Organisations such as Aspect (Autism Spectrum Australia) also offer information and support.
An online autism screening test can help you organise your thoughts before an appointment, but it cannot provide a diagnosis. Before your appointment, it may be useful to record examples of daily challenges, childhood experiences and concerns raised by people who know you well.
Do Treatments for ADHD and Autism Differ?
Yes, although some support approaches overlap. ADHD management may involve a combination of practical strategies, psychological support and, when clinically appropriate, medication. Autism support often focuses on communication, sensory needs, environmental adjustments and the development of relevant skills. The aim is to support the person’s needs and wellbeing rather than to eliminate autism itself.
ADHD vs Autism FAQs
What is the main difference between ADHD and autism?
ADHD mainly affects attention, activity levels and impulse control. Autism mainly affects social communication, sensory processing and the need for routine. Both are neurodevelopmental conditions, and they can occur together. A clinician considers why behaviours occur, rather than looking only at how they appear, to help distinguish between the conditions.
Can a child have ADHD and autism at the same time?
Yes. Since the DSM-5 was introduced in 2013, both conditions have been able to be diagnosed together. Research suggests that a meaningful proportion of autistic children also have ADHD, and vice versa. If you suspect your child may have both conditions, a comprehensive assessment can help clarify their needs.
Is it ADHD or autism if my child won’t sit still?
Fidgeting and restlessness are common in ADHD, but autistic children may also move to regulate themselves or cope with sensory overload. The reason behind the movement matters more than the movement itself. A clinician will consider when and why it occurs, along with other characteristics, to help determine the cause.
Can adults be diagnosed with ADHD or autism later in life?
Yes. Many adults receive a diagnosis after years of feeling different, sometimes following their child’s diagnosis or a period of burnout. An assessment explores childhood history, current difficulties, and daily functioning. Information from someone who knew the person during childhood may also be helpful.
Why are girls diagnosed later?
Girls may mask their characteristics, present with predominantly inattentive ADHD or have less obvious autistic traits. Their difficulties may be attributed to anxiety, shyness or personality rather than an underlying neurodevelopmental condition. As awareness improves, more girls and women are being recognised, although diagnosis may still occur later than it does for boys.
Do sensory issues mean autism?
Not necessarily. Sensory differences are a recognised feature of autism but can also occur in ADHD and other conditions. Sensory sensitivity alone does not establish a diagnosis. An assessment considers the person’s overall characteristics, developmental history and the impact on daily life.
Is hyperfocus a sign of ADHD or autism?
Hyperfocus is commonly associated with ADHD, while deep, long-lasting special interests are characteristic of autism. However, the two can look similar. Differences may include how long the interest lasts, how it develops,s and the role it plays in the person’s life.
Can an online test tell me if I have ADHD or autism?
No. Online screening tools can identify characteristics worth discussing with a healthcare professional, but they cannot provide a diagnosis. A qualified clinician conducts an assessment using relevant interviews, developmental history and standardised tools where appropriate.
If You Need Support
This article is for general information only and is not a substitute for professional advice. If you are experiencing distress, support is available:
- Lifeline: 13 11 14
- Kids Helpline: 1800 55 1800
- Emergency: Call 000.
Conclusion
When ADHD and autism occur together, understanding each person’s unique needs is an important step towards meaningful support. With HelloDoc, individuals and families can explore their concerns with qualified healthcare professionals and discuss suitable next steps. Whether the focus is on ADHD treatment options, managing overlapping challenges, or understanding available support, a personalised approach can help ensure that care reflects the person’s needs, goals,s and circumstances.
HelloDoc (Disclaimer and Liability Terms)
HelloDoc aims to connect users with psychiatry professionals. However, we do not guarantee the accuracy, reliability, or completeness of the information shared. The platform does not warrant any professional medical advice, diagnosis, or treatment. All services are offered “as-is,” and users must assess their relevance independently.
HelloDoc is NOT an emergency response platform. All consultations are by appointment only. If you are experiencing a mental health crisis, please seek immediate assistance from emergency services.
For Mental Health Emergencies in Australia, contact:
- Lifeline: 13 11 14
- Beyond Blue: 1300 224 636
- MensLine Australia: 1300 789 978
- Suicide Call Back Service: 1300 659 467
- Veterans and Veterans Families Counselling Service: 1800 011 046
The information on this website, including blog posts, is for general informational purposes only and is not meant to replace or substitute for professional medical advice, diagnosis, or evidence-based treatment. Always consult a qualified healthcare provider for any medical condition or health-related questions. By continuing to use HelloDoc, you accept these terms and acknowledge that they may change without notice.
