Understanding Aggression in Autism: What’s Really Going On?

Written by Kathryn Best, based on key takeaways from the webinar "Autism/ADHD: Understanding Aggressive Behaviours" presented by Barb Cook, M.Aut., Dip.HSc.—Registered Developmental Educator, NDIS Registered Specialist PBS Practitioner, and Integrative Nutritionist.

“Many neurodivergent kids are deeply empathetic. But when they’re overwhelmed, they may shut down, seem blunt or distant—or lash out. It’s not personal. It’s not bad behaviour. It’s a system on overload.”

When Behaviour is a Message

As a parent or carer of a neurodivergent young person, you may sometimes be on the receiving end of big outbursts, anger, or what seems like aggression. It can be confusing and upsetting. But here's the truth: what looks like aggression is often a cry for help, a sign your child is overwhelmed, misunderstood, or simply trying to cope with too much.

Let’s break it down

Why It Happens

Autistic and ADHD young people can experience the world more intensely than others. Noises are louder. Lights are brighter. Expectations can feel impossible to meet. If they don’t have the tools or support to manage all that, their nervous systems go into overdrive—and their reactions may seem “over the top” to the outside world.

Some key things that might be happening:

• Sensory overload (too bright, too loud, too busy)

• Struggles to understand verbal instructions

• Feeling unsafe or unsupported

• Emotions bottled up until they’re home—then the meltdown comes

Big Emotional Response

For many autistic and ADHD young people, emotions don’t come in gentle waves—they arrive like a tidal surge. These responses can feel intense, fast, and overwhelming. Imagine feeling everything more deeply than others do, every single day.

• What seems like an “overreaction” may actually be the result of sensory overload—bright lights, loud music, or busy crowds can tip someone into a fight-or-flight state.

• The nervous system reacts differently. Some kids become agitated and lash out, while others may shut down or freeze.

• Emotional responses and sensory experiences are often tangled together. A loud sound might trigger fear or frustration, leading to a meltdown—not because of the sound alone, but because of how it feels in their body.

• Kids with ADHD might also struggle with impulse control, switching from joy to anger in seconds without having the tools to stop and think.

• Often, young people try to "hold it together" at school or in public, only to fall apart once they’re in a safe space like home. It’s not manipulation—it’s trust.

Some ways to help:

• Use calming sensory tools like swinging, weighted blankets, or stress balls

• Create consistent routines and downtime after intense environments

• Recognise signs of overload early—irritability, fidgeting, zoning out—and help them take breaks before it builds up

Tips to Help in the Moment

When things escalate, try:

• Speaking slowly and calmly with a caring tone

• Inviting them to sit and take a break

• Using gentle words like, “Let’s help you feel safe”

• Avoiding threats or arguments

• Not restricting their movement

• Helping them name their emotions: “You look upset. Are you feeling anxious about school?”

Communication and Processing

Neurodivergent young people often face challenges with how they process and respond to information, especially during stressful or busy moments.

Some important things to understand:

• Communication can be overwhelming when it happens too fast. They may not be able to take in and respond to information at the speed others expect.

• Understanding spoken instructions can be difficult. They may rely more on visual cues or familiar routines to figure out what’s happening.

• What looks like defiance or a lack of cooperation might actually be confusion or overload.

• They may only process fragments of what was said, making it hard to follow instructions or understand what is expected.

• Being bombarded with too many words or changes can increase stress and lead to shutdowns or outbursts.

Giving them time, breaking information into small chunks, and using visual supports can make a big difference.

Building Emotional Regulation

It’s not about stopping the feelings—it’s about helping them name and manage them. Here’s what can help:

• Understanding their sensory needs

• Offering calming activities like swinging or stress balls

• Creating safe routines

• Allowing time and space to decompress after school

De-Escalation Techniques

When your young person is overwhelmed or showing signs of distress, try to:

• Speak slowly and confidently using a gentle, caring tone of voice

• Invite them to sit down if they’re standing or pacing

• Use calm, positive words: “Let’s help you feel safe and calm”

• Take a break from the conversation so they have space to settle

• Avoid arguing, raising your voice, or responding in a disciplinary way

• Avoid threatening consequences — this can increase fear or fuel aggression

• Do not physically restrain or restrict their movement

• Help them identify what they’re feeling: “You look really upset. Is something bothering you?”

• Gently raise awareness of stress triggers, e.g., “You have an assignment due soon — are you feeling anxious?”

The goal isn’t to control their behaviour. It’s to help them feel safe enough to regain control themselves.

It’s Not Lack of Empathy

Many neurodivergent kids are deeply empathetic. But when they’re overwhelmed, they may shut down, seem blunt or distant—or lash out. It's not personal. It's not bad behaviour. It’s a system on overload.

Final Thoughts

If your young person “holds it together” at school but explodes at home, know this: they feel safe with you. That’s why it comes out there. You're doing better than you think. They don't need a perfect parent—they need a steady one.

Keep going. Keep learning. You're not alone.

About This Resource

This article is based on key takeaways from the webinar "Autism/ADHD: Understanding Aggressive Behaviours" presented by Barb Cook, M.Aut., Dip.HSc.—Registered Developmental Educator, NDIS Registered Specialist PBS Practitioner, and Integrative Nutritionist.

Learn more at:
🌐 www.neurodiversityhub.com
🌐 www.barbcook.com.au

Go to the EPIC Resources Neurodiversity Page for the following information:

• Common types of neurodiversity

• Organisations that support young people and their families

• Webgsites with useful information and strategies to support young people

• Podcasts/Videos with useful information and strategies to support young people

• Support groups for parents/carers caring for young people

• Help lines
  

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