Quick Answer
The ADI-R (Autism Diagnostic Interview-Revised) is a structured caregiver interview and diagnostic assessment used to help diagnose autism spectrum disorder (ASD). An experienced interviewer works through 93 structured items covering your child’s communication, social development, and repetitive behaviors. It typically takes 1½ to 2½ hours, and the way it’s scored shifts somewhat depending on your child’s age.
If your child has been referred for an autism evaluation, there’s a good chance you’ve already heard the term “ADI-R.” Maybe a school psychologist mentioned it. Maybe your pediatrician suggested it. Either way, you’re probably wondering what actually happens during the interview and what it can tell you about your child.
Here’s what you need to know.
A Research Tool That Became a Diagnostic Standard
The ADI, or Autism Diagnostic Interview, started as a research instrument for studying behavioral patterns linked to autism. Clinicians quickly recognized its value as a standardized diagnostic tool in its own right, not just a research aid, and it has undergone one major revision since.
From Research Tool to Clinical Standard
The Original ADI
Developed as a research instrument to study behavioral patterns linked to autism, in both children and adults.
The ADI-R Revision
Revised, shortened, and reorganized into the interview used today, built for a mental age of about 18 months and up rather than one fixed chronological cutoff.
A Clinical Standard
Published by Western Psychological Services (WPS) and used widely in clinical settings and public school systems.
Today, the ADI-R is published by Western Psychological Services (WPS), the same company that produces the ADOS-2. It’s become one of the most widely used diagnostic tools in both clinical settings and public school systems.
The urgency around early, accurate diagnosis is well-founded. A 2015 University of Washington follow-up study examined children who’d received an intensive early intervention called the Early Start Denver Model and found they maintained gains in intellectual ability and language years later, along with continued reductions in autism symptoms. Getting an accurate diagnosis early means treatment, whatever form it takes, can start sooner, and that matters.
What the ADI-R Assessment Actually Measures
The ADI-R consists of 93 structured interview items designed to build a detailed picture of your child’s developmental history. Most clinicians work through the interview in about 1½ to 2½ hours, though the length can vary depending on the complexity of your child’s history.
Here’s something that surprises many parents: unlike the ADOS-2, which involves direct observation of your child, the ADI-R is entirely a conversation between the interviewer and you. The focus is on you as the primary source of information, drawing on your memory of your child’s development from infancy to the present.
The questions cover three core areas tied to ASD diagnosis criteria:
Communication and language skills: Your child’s speech development, how early they began talking, and how well they communicate their needs today.
Social interaction: How your child connects with others, responds to emotional cues, makes eye contact, and engages in play or friendships.
Repetitive and restricted behaviors: Patterns like fixation on specific objects or topics, repeated movements, rigid routines, or unusual use of language.
Most items are scored on a 0-to-3 scale, with higher numbers indicating more atypical behavior, though a few special codes exist for responses such as “not applicable” or “don’t know.” When it’s time to calculate the official diagnostic score, a 3 typically gets reclassified as a 2, since the scoring algorithm works a bit differently from the raw interview scoring. The interviewer also notes when each behavior was first observed and whether it’s still present today.
Why Developmental History Matters
It’s easy to fixate on one specific behavior and wonder if it means something. But the ADI-R is designed to look at the whole picture, not isolated traits that might appear in typical development and disappear on their own.
A child might go through a phase of spinning objects or avoiding eye contact for a few months without any other signs of autism ever showing up. The ADI-R accounts for that. It examines patterns over time, developmental milestones, and how multiple behaviors interact to form a consistent picture.
Specifically, the interview covers medical history and prior diagnoses; general behaviors, past and present; when major developmental milestones were reached; the history of speech and language development; and any destructive or aggressive behaviors.
That depth is what makes the ADI-R more than a checklist. It’s a case history.
What the ADI-R Can and Can’t Do
The ADI-R is a well-validated tool, but it’s not used in isolation. Clinicians are free to use whatever assessment methods they prefer, and most treat the ADI-R as one component of a broader evaluation, often paired with the ADOS-2 to give evaluators a fuller picture. The two tools work together but serve different purposes:
ADI-R
Caregiver Interview
Developmental history
- FormatStructured interview with a parent or caregiver
- FocusDevelopmental history, from infancy to the present
- Length1½ to 2½ hours
ADOS-2
Direct Observation
Present-day behavior
- FormatDirect observation of the child
- FocusReal-time social and communication behavior
- Administered byA clinician trained in ADOS-2 administration
The ADOS-2 captures what your child does in the room. The ADI-R captures the developmental context that brought them there. Together, they’re often described as gold-standard tools for autism evaluations, a professional term rather than an official designation, and neither one on its own establishes a diagnosis. That still comes down to clinical judgment and DSM-5 criteria.
There are limitations worth understanding, especially around age. The 1994 revision that created the ADI-R was designed for a mental age of about 18 months and up, but how well it performs and which scoring approach applies shift with your child’s age. Earlier research found reduced sensitivity in very young toddlers, which is part of why newer toddler- and preschool-specific algorithms have been developed since. If your child is younger, expect more caution in interpreting the results, and don’t be surprised if the evaluator wants to check back in at a later age.
It’s also worth noting that the American Academy of Pediatrics recommends autism-specific screening for all children at 18 and 24 months, a recommendation the CDC also cites, and the tools used at those ages may differ from the ADI-R.
One thing many parents don’t expect: even when the ADI-R doesn’t result in an ASD diagnosis, the process is often more useful than parents anticipate. The questions encourage you to look at your child’s development more objectively. Parents frequently leave with a clearer picture of their child’s strengths and needs regardless of the outcome. If you’re drawn to working with families through this diagnostic process, you can explore top ABA master’s programs to find the right fit for your career goals.
Frequently Asked Questions
Who administers the ADI-R?
The ADI-R is given by an experienced interviewer trained in its administration and scoring. Exactly who’s considered qualified- a psychologist, a school-based evaluator, or another credentialed professional- depends on the practice setting, the publisher’s requirements, and the rules where you live. Schools have their own evaluation obligations under IDEA, but IDEA doesn’t require the ADI-R specifically or name a particular profession to give it.
Is the ADI-R the same as the ADOS-2?
No. The ADI-R is a structured interview with a parent or caregiver about the child’s developmental history. The ADOS-2 involves direct observation of the child by a trained professional. They serve different purposes and are frequently used together.
How long does the ADI-R assessment take?
Most clinicians complete the 93-item interview in approximately 1½ to 2½ hours, though the length can vary depending on the detail of your responses and the number of follow-up questions that arise.
At what age is the ADI-R used?
The ADI-R covers a broad age range, built for a mental age of about 18 months and up, but the scoring approach shifts with your child’s age. Earlier versions of the tool were less sensitive in very young toddlers, which is why newer toddler and preschool-specific algorithms were developed. Whatever your child’s age, expect the results to be considered alongside other assessment tools rather than on their own.
Key Takeaways
- The ADI-R is a structured 93-item interview conducted with parents or caregivers that focuses on the child’s developmental history
- It covers three areas central to ASD diagnosis: communication, social interaction, and repetitive behaviors
- Covers a broad age range, built for a mental age of about 18 months and up, though the scoring approach shifts with your child’s age
- Rarely used alone: most evaluators pair it with the ADOS-2 or other tools for a complete assessment
- Even when an ASD diagnosis isn’t the outcome, the interview process can help parents better understand their child’s developmental pattern
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