At what age is the ADI-R used for a child?

The ADI-R is a careful interview with you, the parent — and it works best once your child has reached a certain developmental stage.

In short

The Autism Diagnostic Interview-Revised (ADI-R) is used for children with a developmental age of at least around 2 years — broadly from toddlerhood through childhood and into adulthood. It is not based purely on calendar age but on developmental level, because the interview asks about social communication and play behaviours that only become meaningful once a child has reached roughly a two-year developmental stage. It is a structured, clinician-led interview with the parent or main caregiver, not a test done directly on the child.

How the ADI-R is used

The ADI-R is a detailed, standardised interview that a trained clinician conducts with you — the person who knows your child's history best. It explores three areas central to understanding autism: social interaction, communication and language, and repetitive or restricted behaviours and interests. The clinician asks both about your child's behaviour now and about earlier development, particularly around the ages of 4 to 5 years where certain patterns are most informative.

Because it relies on a child having a developmental age of about 2 years or more, the ADI-R is rarely the right tool for a very young infant. For younger or pre-verbal children, clinicians choose age-appropriate observation and screening tools instead. The ADI-R is usually used alongside direct observation of the child (such as the ADOS) and a broader developmental picture — no single instrument stands alone.

When this matters for your family

If you have questions about how your child communicates, plays or relates to others, an assessment is the gentle first step — never a label. A clinician decides which tools fit your child's age and developmental stage, and the ADI-R may be one part of a fuller picture for children at or beyond a roughly two-year developmental level.

The Pinnacle way

This is general information, not a diagnosis — a clinical AbilityScore® and any diagnosis are formed only at a Pinnacle Blooms Network centre, under qualified clinician care, never from an app or form. Our clinicians select the right combination of tools, including instruments like the ADI-R where appropriate, and build an individualised plan that may draw on autism therapy tailored to your child's strengths.

Trusted sources

WHO ICD guidance on autism spectrum conditions; the American Academy of Pediatrics and HealthyChildren on developmental assessment and screening; ASHA on communication assessment in children.

Next step — If you would like to understand your child's development, book a developmental review and let a qualified clinician choose the assessments that fit your child best.