Explaining your child’s diagnosis — or possible diagnosis — to siblings and family

One of the things parents often find hardest is working out what to tell the rest of the family. How do you explain autism or OCD to a younger sibling? How do you talk to grandparents who may have their own ideas about what’s “normal”? How do you protect your child’s privacy while also helping the people around them to understand?

There are no perfect answers — every family is different. But there are some principles that tend to help.

Talking to siblings

Children are remarkably perceptive. If a sibling is being treated differently — if there are different expectations, different responses to behaviour, more adult attention in certain moments — they notice. Without explanation, they tend to fill the gap with their own theories, which are often worse than the truth.

Simple, honest explanations, pitched to the sibling’s developmental level, tend to work better than avoidance.

For younger children, something like: “Maya’s brain works a bit differently from yours and mine. Sometimes things that don’t bother you feel really hard for her. We’re learning more about it so we can help her better.“

For older children and teenagers, more detail is usually appropriate and often welcomed. Teenagers can be surprisingly empathetic and effective allies if they understand what’s happening.

Talking to grandparents and extended family

Older generations sometimes have strong views about children’s behaviour — and may interpret autism or OCD through the lens of parenting style, discipline, or dietary choices. This can be painful and isolating for parents who are already navigating a difficult situation.

It helps to be clear about what you’re asking of them. You’re not asking them to fully understand the neuroscience. You’re asking them to follow some specific approaches when they’re with your child — to give advance notice of changes, to avoid challenging the routines unnecessarily, to stay calm when your child is distressed.

Concrete and specific tends to land better than general explanations.

Your child’s right to privacy

As your child gets older, their diagnosis becomes their information to share or not share as they choose. Even with younger children, it’s worth being thoughtful about who you tell and how, and whether your child knows what has been shared.

A useful rule of thumb: share what is necessary for people to support your child effectively. You don’t owe anyone a full explanation, and you don’t need to justify your child’s neurology to people who aren’t involved in supporting them.

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This post is part of the Lumara guide series for parents. Lumara Screen is an evidence-informed online screening tool for parents concerned about repetitive behaviours, rituals, or routines in their child. Free to complete — full personalised report £7.99.

Ready to understand what you’re seeing? The Lumara screening tool takes around 10 minutes to complete and gives you a personalised report you can share with your GP or specialist. Free to start — full report £7.99.