Conditions that can occur with autism

Co-occurring conditions and autism

Several medical, developmental or psychiatric conditions can occur alongside autism. These are called co-occurring conditions.

Nearly three-quarters of autistic children are diagnosed with a co-occurring condition. Co-occurring conditions can appear at any time during development. Some might appear early, whereas others appear only in adolescence or adulthood.

These conditions can affect how your autistic child responds to therapies and supports. That’s why it’s important to diagnose these conditions.

Here are common co-occurring conditions that might be diagnosed in autistic children.

Anxiety

People with anxiety have a range of symptoms including tension, restlessness, hyperactivity, worry and fear. For autistic children, anxiety might show up as asking questions over and over again, hurting themselves, or having trouble getting to sleep.

How common is anxiety in autistic children?
Anxiety is common in autistic children, and around 40% of autistic children have it.

Social anxiety is one of the most common anxiety disorders. Autistic people’s communication differences are sometimes related to social anxiety.

Treatment, therapies and supports for anxiety
Cognitive behaviour therapy (CBT) and relaxation techniques can help autistic children with anxiety. Sometimes medicine might be helpful for children.

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Attention deficit hyperactivity disorder (ADHD)

Many children have difficulty with thinking before they act, sitting still and focusing. But in children with attention deficit hyperactivity disorder (ADHD), these behaviours can have a big effect on their daily lives.

How common is ADHD in autistic children?
Autism and ADHD share some common characteristics. Many autistic children behave in ways that are very similar to ADHD, and 30-60% meet the criteria for an ADHD diagnosis.

Treatment, therapies and supports for ADHD
Health professionals can work with autistic children on strategies for managing ADHD. Doctors will sometimes prescribe stimulant medicines for children diagnosed with ADHD. These medicines improve the way the parts of the brain ‘talk’ to each other. This can help children with attention and self-regulation.

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Bipolar disorder

Bipolar disorder is a psychiatric condition. People with bipolar disorder have both extreme emotional highs (mania) and extreme emotional lows (depression).

The depression can be quite obvious. For example, the person will probably have low mood, lack of motivation, trouble sleeping and poor appetite. Mania can be harder to spot. Its symptoms include extreme self-esteem, less need for sleep, more talking and higher activity levels than usual.

Children who have bipolar disorder have big and quick changes in mood and behaviour. When they’re going through these mood changes, they might also have trouble paying attention, sitting still and regulating their behaviour.

How common is bipolar disorder in autistic children?
There isn’t a lot of research into bipolar disorder and autism, but it suggests that bipolar disorder is diagnosed in only around 7% of autistic children or teenagers.

Treatment, therapies and supports for bipolar disorder
Treatment is usually long term. It often involves medicine. There are some behavioural therapies that can help.

Find out more
National Institute of Mental Health – Bipolar disorder

Depression

Symptoms of depression include low mood, poor sleep and appetite, irritability and a loss of motivation. In children, depression symptoms can also be irritability as well as sadness and low moods.

How common is depression in autistic children?
Depression is diagnosed in 10-20% of autistic children. Depression can be more common among children who feel isolated or different from others or who experience social difficulties, like bullying.

Treatment, therapies and supports for depression
Health professionals often use a combination of medicine and psychotherapy, like cognitive behaviour therapy (CBT), to treat depression.

How well treatment works depends on several things, including the child’s temperament, environment, control over things that cause stress, and experience with other treatments. It also depends on how long the child has had depression and how much support they get from family and friends.

Also, treatments like CBT are talking therapies. This means they’re unlikely to help children who find it difficult to use language to communicate.

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Down syndrome

Down syndrome is a genetic condition.

Most people have 23 pairs of chromosomes. People with Down syndrome have an extra 21st chromosome. This causes characteristic facial features, developmental delays, intellectual disability, poor muscle tone, potential hearing and vision problems, and congenital heart defects.

Down syndrome can be identified with tests during pregnancy. If it isn’t picked up then, it’s usually diagnosed at birth or in early infancy.

How common is Down syndrome in autistic children?
Only a small number of autistic children also have Down syndrome (around 1%). This is because Down syndrome is uncommon, occurring in only 1 in 1100 births. On the other hand, autism is relatively common in children who have Down syndrome. Around 16% of children with Down syndrome are also autistic.

Treatment, therapies and supports for Down syndrome
The health problems associated with Down syndrome can be treated, usually very well.

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Eating disorders

Eating disorders are serious mental health conditions that also affect physical health. The most common eating disorders are anorexia nervosa, bulimia nervosa, avoidant restrictive food intake disorder (ARFID) and binge-eating disorder.

How common are eating disorders in autistic children?
Eating differences are common in autistic children. These differences include avoiding foods, eating non-food items, and having fixed ideas about how food is served. They also include sensory sensitivities to certain types of food, which severely limit the range of food children will eat. About 30-50% of autistic children have diagnosed eating disorders.

Treatment, therapies and supports for eating disorders
A team of health professionals with expertise in different areas usually support children with eating disorders. These health professionals develop individual treatment plans for children.

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Fragile X syndrome

Fragile X is a genetic condition. It’s the most common cause of inherited intellectual disability.

Most boys with this condition have an intellectual disability, sometimes severe. In the early years this would be noticed as developmental delay. Girls with this condition are more likely to have learning difficulties than intellectual disability. Children with the condition have difficulty communicating.

How common is Fragile X in autistic children?
Fragile X is a genetic cause of autism, and autism is relatively common in children with fragile X. But only a small number of autistic children also have fragile X syndrome (around 1%) because fragile X occurs much less frequently than autism.

Treatment, therapies and supports for Fragile X
Treatment usually involves speech pathology, occupational therapy and educational support.

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Gastrointestinal symptoms

The most common gastrointestinal symptoms for autistic people are chronic constipation, abdominal pain, diarrhoea and faecal incontinence. Other problems can include gastro-oesophageal reflux disease (GORD) and stomach bloating.

It’s not clear why autistic children have relatively high rates of gastrointestinal symptoms, but it might be because of differences in diet, altered gut bacteria, or differences in the way the gut functions.

How common are gastrointestinal symptoms in autistic children?
Autistic children and children with developmental delay or disability seem to have more gastrointestinal symptoms than other children. Around 40% of autistic children are diagnosed with a gastrointestinal problem.

Treatment, therapies and supports for gastrointestinal symptoms
Because there are many reasons why a child might have gastrointestinal symptoms, the child will need a thorough medical examination before starting any treatment.

There’s no evidence to support the general use of a gluten-free or casein-free diet. But like some typically developing children, autistic children might have food intolerances, food allergies or food sensitivities. If this is the case, specific diets can help.

Find out more
Autism Help – Gastrointestinal tract problems

Intellectual disability and developmental delay

Intellectual disability can be diagnosed when a child who is 6 years or older has an IQ below 70 as well as difficulties with daily tasks. In children under 6 years, the term ‘developmental delay’ is used when children have significant cognitive and language delays.

Intellectual disability varies from person to person. Autistic children with intellectual disability might have uneven skills, so there might be some things that they’re quite good at and others they find hard.

In most cases, autistic children have more trouble with verbal skills – like talking, listening and understanding – than with non-verbal skills like doing puzzles or drawing.

How common is intellectual disability in autistic children?
In the past, it was thought that 50-60% of autistic children had intellectual disability or developmental delay. But it’s now thought to be 35%, with another 20-25% having borderline intellectual disability with an IQ of 71-85.

This drop might be because IQ testing for autistic children has improved, support and education is better at addressing autistic children’s learning needs, and more children without intellectual disability are being diagnosed with autism.

Treatment, therapies and supports for intellectual disability
There can be significant improvements over time in some very young autistic children who have developmental delay and get good early therapy and support. Other children who have a more significant developmental delay might still have a lower than typical IQ when they’re older.

Intellectual disability is a lifelong condition, but supports can help children to learn skills and make the most of their strengths.

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Language delay, speech disorder and developmental language disorder

Language delay is when young children have difficulties understanding and/or using spoken language. If a child has a language delay that doesn’t go away, this might be a sign of a developmental language disorder. Children with developmental language disorders have language difficulties that affect their everyday lives. For example, it’s hard for them to learn to read or follow verbal instructions.

A speech (sound) disorder is when children have difficulty pronouncing the sounds in words. Children with speech disorders don’t necessarily have language delay or language disorder.

Not all children who have language delay have problems with speech sounds.

How common are language delays and disorders in autistic children?
Autistic children have different ways of communicating with others. They might have difficulties with aspects of language – for example, difficulties with learning words or grammar. They might also have difficulty with learning speech sounds, but this is less common.

Of autistic children, 40% are also diagnosed with a language disorder. Around 30% of autistic people might be non-speaking, which means they don’t use their voices to communicate verbally.

Treatment, therapies and supports for language delays and language disorders
Speech pathologists help children with speech and language delay or difficulties. They might recommend individual or group programs that build language skills. They might also help children develop other ways to communicate, like gestures, pictures or picture boards, Key Word Sign or speech-generating devices.

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Motor difficulties

Children with motor difficulties might have difficulties with gross motor skills, like balancing, running or climbing. Or their difficulties might be related to fine motor skills, like grasping objects, writing or using cutlery. Motor difficulties can also affect children’s mouths, making their speech hard to understand.

Motor difficulties might be caused by underlying muscle weakness or coordination difficulties. These difficulties can affect the way children do daily activities.

How common are motor difficulties in autistic children?
About 80% of autistic children have some form of motor difficulty. Motor difficulties can happen in babies, children and adults, often before autism characteristics become clear. Some researchers think these difficulties might be an early sign of autism.

Treatment, therapies and supports for motor difficulties
Occupational and physical therapy can help children with motor difficulties.

Find out more
Skills for action – The many reasons why autistic children have difficulties with posture and movement

Obsessive compulsive disorder (OCD)

Obsessive compulsive disorder (OCD) is a type of anxiety disorder.

People with OCD have thoughts that they don’t want but can’t get out of their heads. They might behave in repetitive and compulsive ways to deal with these thoughts. For example, they might wash their hands over and over again, or they might arrange or count objects in patterns.

Some people experience obsessive thoughts about flaws in their appearance that other people can’t see. This type of obsessive thinking is called body dysmorphic disorder.

How common is OCD in autistic children?
It’s hard to know how common OCD is among autistic children because the repetitive behaviour in each condition looks similar. But researchers think that around 10% of autistic children have OCD.

Research suggests that there might be some genetic links between OCD and autism.

Treatment, therapies and supports for OCD
OCD can be treated with behavioural therapy, cognitive therapy, medicine or a combination of these.

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Seizures and epilepsy

Epilepsy is the name for a range of brain conditions where a child has or is at risk of having repeated and unpredictable seizures because of abnormal electrical activity in the brain.

The abnormal electrical activity in the brain causes odd sensations and abnormal movement or behaviour. These are called convulsions or seizures. When a child has a seizure, there’s usually a temporary period of unconsciousness, a body convulsion, unusual movements or staring spells.

It can be hard to spot epilepsy in autistic children. This is because seizure symptoms can include things like a lack of response when their name is called or repetitive hand or body movements, which are similar to some autism characteristics.

How common are seizures and epilepsy in autistic children?
Of autistic people, 20-30% have epilepsy. Seizures are most common in children under 5 years and in teenagers.

Autistic people with moderate to severe intellectual disability, autistic people with neurological conditions (for example, cerebral palsy), or children who show regression in their skills are more likely to develop epilepsy.

There might also be a genetic relationship between seizures and autism.

Treatment, therapies and supports for seizures and epilepsy
Treatment usually involves anti-epileptic medicine. You can also take steps to minimise the effects of epilepsy. These steps include making sure your child takes medicine on time, gets enough good-quality sleep, and avoids situations that cause stress.

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Sleep problems

The most common sleep problems in autistic children are trouble falling asleep and staying asleep, nightmares, night terrors and sleepwalking.

How common are sleep problems in autistic children?
Sleep problems are common among autistic children. About two-thirds of autistic children might have sleep problems at some stage.

Treatment, therapies and supports for sleep problems
Good sleep habits can help. These habits include:

cutting out drinks with caffeine in the afternoon and evening
getting sunshine and exercise throughout the day
avoiding screen use in the hour before bedtime
having a bedtime routine.

Medicine is another option, but health professionals generally recommend this only if behavioural strategies have failed. Melatonin is the only medicine currently thought to be helpful.

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Tourette disorder

Tourette disorder is a tic disorder. Tics are sudden, repetitive and uncontrollable movements and sounds. Tourette disorder is when children have movement tics and sound tics for longer than a year.

How common is Tourette disorder in autistic children?
About 5% of autistic children have Tourette disorder and another 9-12% have tics of some kind. Tourette disorder or motor tics are more common in children with moderate to severe intellectual disability.

Treatment, therapies and supports for Tourette disorder
Education and reassurance can help children understand the tics and learn strategies to manage them. Doctors might recommend specific behavioural therapies, or medicine, if the tics are severe or affecting daily life.

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Tuberous sclerosis

Tuberous sclerosis is a genetic condition that causes abnormal growths in the brain and other vital organs. Symptoms can include white patches on the skin, facial rashes, seizures, hyperactivity and intellectual disability.

How common is tuberous sclerosis in autistic children?
Tuberous sclerosis isn’t very common among autistic children (0-4%). It’s more common if the person also has a seizure disorder (8-14%).

Treatment, therapies and supports for tuberous sclerosis
Treatment focuses on managing symptoms and supporting the person and family.

Find out more
Tuberous Sclerosis Australia

Getting help

If you think your autistic child has another condition, talk with a health professional like your child’s GP, nurse or paediatrician. Depending on the condition, the professional might be able to order some tests, including a genetic test, or refer you to a specialist for further assessment and treatment.