Aggressive behaviour and self-injury in autistic children and teenagers: what is it?

Autistic children and teenagers sometimes express their emotions through aggressive behaviour.

Sometimes the aggressive behaviour is directed towards objects or other people. For example, they might hit or kick people or throw objects.

Sometimes the aggressive behaviour is directed towards themselves. When children and teenagers hurt themselves, it’s called self-injurious behaviour. An example is head-banging.

When autistic children and teenagers feel completely overwhelmed, they can have meltdowns. Meltdowns are a sign of distress. Children and teenagers lose control of their behaviour and find it very hard to calm themselves.

Responding to aggressive behaviour from autistic children and teenagers

You can’t prevent every aggressive outburst from your autistic child. So it’s important for you to have strategies to deal with aggressive behaviour when it happens.

Stay calm
Most aggressive outbursts happen because your child has strong feelings and can’t communicate them. By managing your own feelings and staying calm, you’re modelling good coping behaviour. And when you’re calm, it’s also easier for you to respond appropriately to your child’s needs.

Limit what you say
During an aggressive outburst, your child will be feeling very stressed. It’s hard for your child to process what someone else is saying when they’re feeling stressed. It can help to use short phrases or even just a couple of words. For example, say ‘Sit down’ rather than ‘Lachlan, come over here and sit down’.

Move your child to a safer place
Where possible, try to make sure your child isn’t close to anything that could hurt them or other people – for example, shelves that could fall over or glass objects. You might also need to get other people to move somewhere safe.

Consider visual cues
Visual cues can help in these situations. For example, you might have a picture of a quiet place in your home that your child can go to.

Seek help if you need to use physical restraint
If you find you have to use physical restraint when your child has an aggressive outburst, speak with your child’s paediatrician or other professional about other options. Physical restraint can be dangerous to both you and your child. It can also increase your child’s anxiety and make the situation worse.

Responding to self-injurious behaviour in autistic children and teenagers

These strategies can help you handle self-injurious behaviour when it happens.

Stay calm
When your autistic child is distressed, stay calm and use a calm tone of voice. This can reassure your child that they’re safe and you’re there to support them.

Pause demands or expectations
Pause any activities or tasks that might be making your child feel stressed. Avoid giving more instructions or requests. Also avoid talking about feelings. You can come back to the activity or task when your child is feeling calm again.

Change the environment
If your child is hurting themselves because their environment is overwhelming, think about what you can change so your child feels more comfortable. For example, you might be able to reduce noise by moving your child to a different room or giving them noise-cancelling headphones. Or perhaps you can reduce your child’s physical discomfort by helping them change into their favourite clothes or get some fresh air.

Remove harmful items and provide alternatives
Remove items that are causing your child harm, and give them a safer alternative. For example, if your child is hitting their head with a book, you might swap the book for a pillow. If your child is biting themselves, you could give them a snack or chewing toy instead.

Encourage your child to do another activity
Try to redirect your child’s attention to a preferred activity or pleasant sensory experience – for example, getting a tight hug, jumping on the trampoline, hiding under the blankets, reading a book, watching a TV show, lining up blocks or taking deep breaths.

Praise your child
Praise your child calmly and gently if they gradually calm down and stop the behaviour with your support. Use descriptive praise so your child knows what they did well and what they can do next time. For example, ‘I love that you chose to jump on the trampoline instead of hitting your head when you felt upset’.

If your child is ever in immediate or life-threatening danger, call emergency services on 000 straight away. It’s also important to get medical attention for your child if they have any serious injuries.

Why autistic children and teenagers behave aggressively or hurt themselves

Autistic children and teenagers might behave aggressively or hurt themselves because they:

• have trouble understanding what’s happening around them – for example, what other people are saying
• have difficulty expressing their feelings or communicating their wants and needs
• are very anxious or stressed
• have sensory sensitivities, like an oversensitivity to noise or a need for stimulation
• are in pain or don’t feel well and can’t communicate how they feel
• want to escape from stressful situations or activities
• feel angry or out of control because of a change in routine or plan.

Understanding aggressive or self-injurious behaviour in autistic children and teenagers

If you can understand why your autistic child is behaving aggressively or hurting themselves, you can develop a plan for avoiding the behaviour in future.

When you’re both feeling calm, you could talk with your child about the behaviour and what they think causes it.

If your child can’t tell you what’s worrying them or doesn’t understand it themselves, you could use a diary to help you understand your child’s behaviour. Try keeping a diary of the behaviour for 1-2 weeks, noting what happens before and after the behaviour.

Keep the following questions in mind:

• What time of the day is the behaviour happening?
• What sensory input is your child dealing with?
• Is your child tired or hungry?
• What was your child doing just before the behaviour – for example, getting ready for school, transitioning from one activity to another, or completing homework?

Avoiding aggressive or self-injurious behaviour in autistic children and teenagers

When you understand what’s causing your autistic child’s aggressive or self-injurious behaviour, you can create an environment that helps your child to stay calm. You can also help your child to learn skills to manage their behaviour.

These strategies can help:

• Change the environment if sensory sensitivities are an issue for your child. For example, have a quiet space your child can go to, or let your child try noise-cancelling headphones or earplugs.
• Prepare for transitions or changes in routines by giving warnings and using visual schedules.
• Help your child learn to recognise, understand and manage their emotions.
• Help your child develop communication skills. This might include words, phrases, hand signals or cards they can use if they’re feeling upset, angry or overwhelmed.

Professional help for aggressive or self-injurious behaviour in autistic children and teenagers

An experienced professional like a paediatrician or psychologist can help you understand and handle your child’s aggressive or self-injurious behaviour.

Speaking to a professional can help if you’ve already tried a range of strategies and you’re still concerned about your child’s behaviour.

Looking after yourself

Looking after yourself physically, mentally and emotionally gives you the energy you need to handle your child’s challenging behaviour.

You can look after yourself by:

• eating well and doing some physical activity
• trying to get enough rest or sleep
• making time for things you enjoy
• practising self-compassion.

Seek help for yourself if you’re distressed or you just want to talk about how your child’s behaviour is affecting you. Your GP, a psychologist or a counsellor is a good person to talk to about this.