How do I explain my child's diagnosis to their brothers and sisters?

The short answer

Begin with what the sibling has noticed and the information they need, not a complete clinical history. Speak with the diagnosed child about what can be shared, using the communication and decision-making support they need. Explain the diagnosis in plain, accurate terms, then connect it to one familiar example: 'ADHD can make holding a series of instructions hard, so we use a list.' Also say what the diagnosis does not mean. It does not make hurt acceptable, decide every preference or make the sibling responsible for helping. Tell the sibling which parts are private, but do not give them a secret they cannot reasonably hold; agree a short sentence they may use when others ask. Invite feelings without expecting gratitude or closeness, and say when you do not know an answer. Return to the conversation as children grow and family circumstances change.

• Start with the sibling's observations and questions rather than a diagnostic lecture.
• Involve the diagnosed child in deciding what personal information can be shared.
• Explain one relevant difference and what adults are doing to support it.
• State that diagnosis does not excuse harm or give the sibling a caring role.
• Agree what is private and provide a truthful sentence for questions from other people.