The Autism Diagnosis Interview, Revised (ADI-R) is one of two autism assessment tests that are considered the “gold standard” for determining an appropriate autism diagnosis. Getting a proper diagnosis of where a client is on the autism spectrum helps medical professionals, such as Applied Behavioral Analysis (ABA) therapists, develop a treatment plan that supports their client’s mental and emotional health. 

Many children are diagnosed with autism at around 2 years old, but adulthood autism diagnoses are increasingly common. The ADI-R helps clinicians separate potential autism signs from symptoms of other conditions.

What is the ADI-R?

The ADI-R is specifically used in the diagnosis of children who might be on the autism spectrum. When used alongside the Autism Diagnostic Observation Schedule, second edition (ADOS-2), the two tests confirm multiple points where the child can grow. 

An appropriate autism diagnosis at the earliest possible age helps the child learn to navigate a neurotypical world, improve their communication and social skills as much as possible, and avoid emotional struggles that might lead to depression and anxiety later in life. 

Parents often report problems to their pediatrician first. They are usually concerned about slowing development, changes in development, regression, or failing to meet certain milestones such as saying words, creating short sentences, playing with other children, or making eye contact. 

The ADOS-2 is a survey involving direct clinical observation of the child in structured and semi-structured scenarios. Together, these two examinations help ABA therapists or pediatricians determine where a child is on the autism spectrum and begin developing a treatment plan.
 

How Is the ADI-R Administered?

The ADI-R is administered by a professional psychologist or clinician in a structured setting. The ADI-R interview is conducted in the home so children do not have to spend time in an unfamiliar setting. It takes between one and two hours.

The interview process is directed at the parents or caregivers who are most familiar with the child’s development and behavior, so they can knowledgeably discuss how it has changed.
The ADI-R includes 93 questions about the child’s language, communication, social development, interests, and other behaviors. Getting the parents’ or caregivers’ perspective on their child’s development over months or years is one of two essential steps in getting an appropriate diagnosis. 

Answers to questions have numerical values attached to them, and the total score at the end of the exam will be used among other examinations to determine how serious the child’s autism diagnosis is. The number scale is zero to three, with zero being no reported atypical behavior, while three points to more severe developmental problems.

What to Expect During the ADI-R

Questions in the ADI-R are divided into several areas, including: 

  • Communication and language skills. The clinician will ask the parent about the child’s appropriate word use, speech development including grammar comprehension, and ability to sustain a conversation appropriate to their age. 
  • Social interaction. The interviewer will ask about the child’s interactions with their parents, other adults, and other children, including how they respond emotionally, how they show their emotions (especially when upset), and whether they interact with others to play or if they typically play alone.  
  • Repetitive and obsessive behaviors. Stereotypical autistic behaviors such as stimming, developing rituals, and rejecting certain items or foods because of sensory issues begin to develop in childhood. Questions in this section revolve around noticing these behaviors, their severity, and their frequency. This includes questions about destructive behaviors, including self-harm such as skin-biting or head-banging. 

The interviewer will start with questions regarding the child’s early development, in part to determine when changes began to appear. Often developmental changes become noticeable between 6 months and 2 years old. 

Next, the interviewer will ask about the child’s current verbal, social, emotional, and behavioral development. This includes questions about memory, physical activity level, and motor skills. Children who struggle to remember events or people, move less, or have difficulty with fine motor skills are more likely to be on the autism spectrum.

Since the ADI-R is a longer interview, this test may be conducted on a different day than the ADOS test. Again, your child will not need to leave home as a clinician will come to you. 

If you are concerned that your child is on the autism spectrum, ask your pediatrician for help as they can refer you to specialists.

The History of the ADI-R

The ADI-R was developed in 1989 by Dr. Ann LeCouteur and her colleagues. The original interview was not a diagnostic tool for clinical settings. Instead, it was intended as a research tool to assess the behavior of children or adults who may have autism and who were at least 5 years old but had the mental age of about a 2-year-old. The interview was effective at separating signs of autism from other potential clinical issues, so health professionals began to apply it in clinical settings to support other tools for diagnosing children with developmental conditions.

LeCouteur and her colleagues saw the benefits of this interview and revised it in 1994, creating the ADI-R. Their adjustments led this interview/diagnostic tool to become one of the more helpful methods for diagnosing autism in children, while also making the interview shorter so children aged 2 and younger could benefit.

A recent review of the ADI-R and the ADOS tests found that, although they were helpful tools in some settings, they tended to “normalize” certain types of behaviors as directly associated with autism. This could be problematic for two reasons: 

  • Young children with psychosis may be misdiagnosed, as ritualistic and stereotyped behaviors were associated with this condition.
  • Children who have milder autism symptoms, who do not display repetitive or stereotyped behavior, who have better language skills, or who have non-typical autism symptoms are more likely to go unnoticed.

    People who receive adulthood diagnoses of autism often have milder symptoms, which clinicians fail to notice in childhood. An earlier study from 2008 found that some cases of childhood onset schizophrenia had similar symptoms to autism, which could confuse the diagnosis and potentially delay treatment. 

Getting the Best Diagnosis Possible

While the ADI-R is one of the more important and effective clinical diagnostic tools, especially alongside the ADOS, it is not the only approach to diagnosing autism. Your primary caregiver will also examine: 

  • Your child’s medical history.
  • Their developmental history as understood by your pediatrician.
  • Their behavioral history aside from ADI-R questions.
  • Family history, which can illuminate potential hereditary or genetic conditions.

Your pediatrician might also examine: 

  • Your child’s general physical health.
  • Growth parameters including head circumference.
  • Neurology. 
  • Skin.
  • Potential dysmorphic features.

Clinicians will not rely solely on the ADI-R and ADOS for an autism diagnosis. Combining examinations leads to the best outcomes and most effective treatment plan.

References

Making a Diagnosis of Autism Spectrum Disorder — A Closer Look. (July 2020). Centers for Disease Control and Prevention (CDC).
Autism Diagnostic Interview, Revised (ADI-R). Pearson Clinical.
Autism Diagnostic Interview-Revised (ADI-R). (2006). Western Psychological Services.
Autism Diagnostic Interview. LoveToKnow.com.
ADI-R and ADOS and the Differential Diagnosis of Autism Spectrum Disorders: Interests, Limits and Openings. (November 2019). L’Encephale.
Use of the ADOS and ADI-R in Children With Psychosis: Importance of Clinical Judgment. (January 2008). Clinical Child Psychology and Psychiatry.