Overview

This article explains the key differences and similarities between Attention-Deficit/Hyperactivity Disorder (ADHD) and autism, including their signs, symptoms, and diagnostic criteria. It explores overlapping characteristics such as sensory sensitivities, difficulties with emotional regulation, intense focus, and repetitive movements. The article also discusses how these conditions may present differently in children, adolescents, and adults. It explains that some individuals may have both ADHD and autism, commonly referred to informally as AuDHD. Additionally, it outlines the assessment process in Australia, the roles of GPs, psychologists, and psychiatrists, and when to seek professional support.

ADHD vs Autism: Signs, Symptoms, and Diagnosis Explained

The two conditions, ADHD and autism, are often discussed together. This can be useful, but it can also lead to the two conditions being confused with each other.

If a routine is not consistent, a child may be distractible and easily frustrated. It is difficult for a teenager to make friends and maintain their order. An adult might have some trouble handling noisy surroundings, easily become tired after being around people, and have trouble with deadlines as well. 

Is it ADHD, autism, or possibly both?

There is no "quick answer. This is because there are similarities between each one. There can be a different meaning behind the same behaviour. Diagnosis must be based on the life and experiences of the individual and not on his or her symptoms. 

What is the difference between autism and ADHD?

ADHD is simply a long-term lack of attention and/or hyperactivity and impulsivity. It can also have different meanings and can cause problems in focusing. May result in forgetting appointments, remembering to start and do chores, managing time, misplacing items and starting activities.

Many people with ADHD can also present with issues of executive function. This implies that planning and organisation is a challenge for this person. Talking to a qualified professional, like a psychiatrist, to diagnose ADHD, can help decide if a formal assessment is needed, if these difficulties are interfering with everyday life.

The pattern of autism is different. It includes social communication and social interaction differences, and restricted/repetitive behaviours, interests or activities. Sensory experiences may also vary, and some autistic individuals may struggle with some changes to routine.

A lot of common overlap remains.

Noisy shopping malls can take them both out, for instance. Both might have a hard time regulating their emotions, and both might get completely absorbed in an interesting topic. Often the separation of the conditions is not much more than how symptoms and behaviours look and are presented on the whole. 

Where do ADHD and autism overlap?

There are some experiences that you can have with both conditions.

Sensory sensitivity: Certain symptoms might be seen as the same in ADHD and autistic individuals. They can become overwhelmed when there are lots of textures and lots of light in a busy environment. In general, sensory symptoms can occur in both.

Emotional regulation: Difficulty in emotion regulation is seen both in condition and post-condition and may manifest as an intense, provocative emotion or a prolonged time of not being able to calm down after an emotion.

Intense focus: ADHD and autism can both involve an intense focus on other things.

Repetitive movements: ADHD and autism can show repetitive movements, like stimming and fidgeting.

Although there are similar symptoms in both autism and ADHD, none of the symptoms listed is diagnostic for either disorder. 

ADHD vs autism symptoms checklist

A checklist can make the differences easier to understand, but it isn't a diagnostic test.

It is worth keeping this table in perspective. Someone does not need to identify with every ADHD trait to have ADHD, and the same applies to autism.

ADHD vs autism in children

Typical behaviors and developmental delays are most likely first detected by parents. It is easy to see that something is abnormal; what the reasons are is different.

Symptoms of autism may present themselves as difficulties with communication and social interactions. No response, odd gestures, and varied responses to names are examples in autistic children. They may also have trouble playing with others, show a focus of interest, problems with various senses, or become upset when their daily routine is disrupted.

Some behaviors that may be associated with ADHD include: fidgeting, being extremely restless, difficulty concentrating, high impulsivity, difficulty sustaining focus, and not working on a task. These behaviors can range from interrupting others, trouble waiting turns, losing possession too quickly, and not being able to read and follow directions.

Why not to rely on a checklist in distinguishing the signs of autism and ADHD in toddlers is because, at this age, activity levels, impulsivity, and difficulty focusing and being distracted are all normal. Development is normal in all children, but in different ways for each child.

Parents who detect concern about their child's development and behaviour may be referred to a GP, which can result in a suitable referral. 

Signs of ADHD vs autism in adolescents

All those usual tests of life at adolescence can have a profound effect on both symptoms of autism and symptoms of ADHD. This can be manifested in greater expectations for self-control and personal responsibility, and greater demands for homework.

The needs of ADHD can lead to problems with organisation and task completion in ADHD. This can occur even if one is aware of what is expected.

Being a teenager with autism can be tough at secondary school. The needs and unwritten “rules” of friends are continuously evolving. The demands placed on school are even greater and more complex.

A few young people either deny or cover up some of their symptoms of being autistic. They become aware of the behaviours of others around them and adjust to them (imitate); on the outside, they may seem to have everything together, but they have little to no energy left.

Symptoms for girls and women with ADHD and/or autism may not be evident; they learn to manage their symptoms and find their own way to cope and deal with their difficulties without causing disruption. As a result, there is very little to no problematic behaviour observable. 

ADHD vs autism in adults

Someone with ADHD may find it difficult to pay bills and schedule appointments, and they may also have a problem organising jobs and estimating the time needed for some jobs in the house. For some adults, the signs of hyperactivity may be more in the form of being physically restless, but being in constant motion and always feeling "on the go.

An adult on the spectrum struggles a lot with social communication and with changes in seemingly peaceful environments; such changes are difficult to manage. Some may enjoy social activities, but need a lot of time to recharge and recover from social stimulation.

Most people have experiential coping mechanisms by adulthood. May have specific routines they follow in detail, may be avoiding specific places and/or may be mimicking social behaviours intentionally. The following strategies can help you make difficulties less noticeable to other people.

That's why you should not be able to tell the difference between the signs of adult autism and signs of ADHD by scanning the website for a few traits. 

Can you have ADHD and autism?

Yes. Some individuals may qualify for both ADHD and autism. The term AuDHD may be familiar to you from the web. Does not refer to a unique diagnosis of autism and ADHD, but rather an informal term for the co-occurrence of these conditions.

Sometimes these two can give experiences that are opposite to one another. A person might feel much more relaxed when their agenda is predictable, but also have a hard time organising their time sufficiently to have a routine. They may have a great passion for a particular subject but have a huge struggle to undertake a normal job.

That's why it is significant not to exclude one disease because some of the characteristics appear to be more common with the other. 

How are ADHD and autism diagnosed?

There is no one test to determine if someone has ADHD versus autism. Answers to an online questionnaire can be helpful in determining whether a person feels it's worth seeking help from a professional but cannot diagnose him or her.

An ADHD evaluation takes into account the person's pattern of inattention and/or hyperactivity and impulsivity, when the problems started, how they interfere with functioning, and whether another explanation exists for the problems.

Assessment for autism considers social communication and interaction, restricted/repetitive behaviours and interests, developmental history, and current functioning. Sensory differences can also be taken into account.

One of the accepted diagnostic systems is the DSM-5-TR. There are further guidelines for the assessment of ADHD and autism available in Australian clinical guidelines.

Assessment will vary by age. Parents, carers and teachers with a child might be asked to comment on development and behaviour. Sometimes, combined with an adult, old school reports or information from family members can help to establish what was happening in childhood. 

Should you seek a Psychiatrist or psychologist for diagnosis?

There isn't one professional who is automatically the right choice for everyone. Psychiatrists are medical doctors who can diagnose ADHD and autism and prescribe medication where appropriate.

ADHD and autism assessment in Australia

A GP is a sensible first port of call for many. You can describe what you have observed, discuss the impact of it on daily life and ask about the possibilities of assessment.

You may have to attend more than one appointment for the assessment. The price also depends on the professional, the kind of evaluation and the service being utilised.

Medicare rebates are applied to certain services; however, there is no one Medicare rebate for every ADHD and/or autism assessment. Eligibility will differ depending on the service, provider, referral and Medicare Benefits Schedule item. Before booking, it's good to review the current rules, as there could be unanticipated fees.

For some, another option is telehealth. This may be especially helpful if specialized services are not readily available or it is hard to get to an appointment. The availability of conducting an assessment via telehealth varies from person to person and assessment to assessment.

In addition, it may be helpful to know how autism diagnosis Australia services operate, especially when developmental history and ongoing social or behavioural patterns are taken into account when exploring pathways away from an ADHD diagnosis. 

When should you seek an assessment?

Don't try to determine the cause of a child's behavior before requesting assistance, whether the cause is ADHD or autism. Talk to a GP or another suitable health professional if any of the following difficulties are having an impact on school, work, relationships, or day-to-day life: attention and organization, sensory experiences, and difficulty coping with changes in their social communication.

A diagnosis is based on more than recognising a certain number of symptoms. The clinician will look at the person's history, the circumstances in which difficulties occur, and their impact on everyday functioning.

Addy is sometimes the answer. Autism is sometimes the answer. In some instances both are met, and in others, one is more apparent during evaluation. The intention is to gain insight into what is happening, to find suitable support for the person. 

Getting the Right Support for ADHD or Autism 

While there is some overlap in a few respects, autism and ADHD are distinct conditions and can manifest themselves in different ways in various individuals. Talk to a psychologist or psychiatrist if you or someone you know continues to have trouble with maintaining attention, communicating socially, daily functioning, sensory processing, or emotional regulation, and determine if an evaluation might be necessary.

For additional assistance, HelloDoc offers access to healthcare mental health services in Australia  professionals via online pathways of healthcare. When symptoms are impacting on work, relationships, or general wellbeing, it can be helpful to consider mental health care in Australia. 

Frequently Asked Questions About ADHD and Autism

1. Can you have ADHD and autism at the same time?

Yes. A person can meet the diagnostic criteria for both ADHD and autism. The two conditions can share some characteristics, such as sensory difficulties, emotional regulation challenges, and intense interests, but they are separate conditions with different diagnostic criteria. A comprehensive assessment can help determine whether someone has ADHD, autism, both, or another explanation for their difficulties.

2. How can you tell the difference between ADHD and autism?

ADHD is primarily associated with persistent patterns of inattention and/or hyperactivity and impulsivity, while autism involves differences in social communication and interaction alongside restricted or repetitive behaviours, interests, or activities. Because some traits overlap, the difference cannot usually be determined from a single symptom or online checklist. A clinician considers the person's developmental history, symptoms and how they affect everyday functioning.

3. Can ADHD be mistaken for autism?

Some ADHD traits can look similar to characteristics associated with autism, particularly difficulties with social situations, emotional regulation, sensory experiences and attention. However, having a few overlapping traits does not mean that someone has autism. A detailed assessment looks at the overall pattern of behaviour and development rather than relying on individual symptoms.

4. What happens during an ADHD or autism assessment in Australia?

An assessment usually involves discussing current difficulties, developmental history and how symptoms affect everyday life. Depending on the person's age and circumstances, a clinician may also gather information from parents, carers, teachers or family members. The assessment process and number of appointments can vary depending on the professional, the condition being assessed and the individual's circumstances.

5. Can adults be diagnosed with ADHD or autism?

Yes. ADHD and autism can both be diagnosed in adults. Some people reach adulthood without receiving a diagnosis because they have developed coping strategies or learned to mask certain difficulties. An adult assessment may consider current symptoms as well as evidence of characteristics or difficulties during childhood.

6. Should I see a GP, psychologist or psychiatrist for an ADHD or autism assessment?

The most appropriate starting point depends on your circumstances and the type of assessment required. A GP can discuss your concerns and help identify an appropriate referral pathway. Psychologists with suitable qualifications and experience can conduct assessments within their scope of practice, while psychiatrists are medical doctors who can diagnose these conditions and prescribe medication where appropriate.

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Conclusion

ADHD and autism are distinct neurodevelopmental conditions, although they share certain characteristics that can make them difficult to distinguish. Their symptoms and effects on daily life vary from person to person, and some individuals may meet the diagnostic criteria for both conditions. Online checklists and individual symptoms cannot provide a definitive diagnosis; a qualified healthcare professional must consider developmental history, behavioural patterns, and everyday challenges during an assessment. Seeking appropriate professional guidance can help individuals and families better understand their needs and access suitable support.