Autism Diagnostic Observation and Interview

What is autism?

• Autism / ASD is a lifelong neurodevelopment condition affecting how people perceive the world and interact with others

• ASD is the official term used in the DSM-5 and subsumes earlier diagnoses such as Asperger’s and ‘Childhood Disintegrative Disorder’

What neurodevelopment disorders are classified under the DSM-5?

• Intellectual (learning) Disability

• Autism

• Specific Learning Disorder

• Attention Deficit/ Hyperactivity Disorder (ADHD)

What are the DSM-5 criterions for ASD diagnosis?

• Criterion A – persistent deficits in reciprocal social communication and social interaction

• Criterion B – restricted, repetitive patterns of behaviour, interests, or activities

• Criterion C – symptoms must be present in the early developmental period

• Criterion D – symptoms cause clinically significant impairment in social, occupational, or other important areas of functioning

• Criterion E – these disturbances are not better explained by intellectual disability or global developmental delay

What is the ICD-11 criteria for ASD diagnosis?

• Persistent deficits in initiating and sustaining social communication and reciprocal social interactions that are outside the range of typical functioning, given the person’s age and level of intellectual development

• Persistent restricted, repetitive, and inflexible patterns of behaviour, interests, or activities that are clearly atypical or excessive for the person’s age and sociocultural context

• The onset of the disorder occurs during the developmental period, typically in early childhood

• Characteristics might not fully manifest until later in life, due to increased social demands

• Characteristics result in significant impairment in personal, family, social, educational, occupational, or other important areas

Why is diagnosis important and beneficial for those with ASD?

• A formal diagnosis can help people qualify for educational accommodations (e.g. ILPs, EHCPs), workplace adjustments, speech or occupational therapy, mental health support, and disability benefits

• Many autistic people report relief after diagnosis as it explains lifelong experiences or difficulties, and can enable them to become empowered with their identity as an autistic person

• Earlier identification can support language development, emotional regulation, school success, and day-to-day living

How does acquiring an autism diagnosis work?

1. Talk to someone for advice, like a GP, Health visit (for children under 5), Special educational needs co-ordinator

2. Have an autism assessment, where an assessment team will run an assessment which will comprise of watching how the person or child interacts with other people, speak to people who know the person or child etc

What did Russell et al. (2022) find about diagnostic trends over time?

• Examined how autism diagnoses changed in the UK between 1998 and 2018 using large healthcare database (Clinical Practice Research Datalink)

• They found that autism diagnosis increased over 20 years following an exponential trend

• Although more males are still diagnoses more often, growth in diagnosis was faster for females

• Slight rising levels of diagnosis in adults over time

What assessment tools are used in autism diagnosis?

• Screening tools - used to identify whether a person a may need a full diagnostic assessment e.g. Ages and Stages Questionnaire (ASQ-SE2), Childhood Autism Spectrum Test (CAST)

• Diagnostic/comprehensive assessment tools - used by trained clinicians as part of a full diagnostic assessment

• Diagnostic tools should not be used in isolation for a formal diagnosis, and it is advised that a combination of tools (e.g. AIR-R and historic records alongside ADOS-2) are used that provide different types of information

What are the diagnostic assessment tools for autism diagnosis?

• Autism Diagnostic Observation Schedule (ADOS-2)

• Autism Diagnostic Interview-Revised (ADI-R)

• Childhood Autism Rating Scale (CARS-2)

• Diagnostic Interview for Social and Communicative Disorders (DISCO)

• Ritvo Autism Asperger Diagnostic Scale Revised (RAADS-R)

What are the training requirements and costs of autism assessment tools?

• The ADOS-2 and ADI-R are restricted with no public access, and require formal training before being certified to use them, often with training providers requiring proof of qualifications for eligibility

• Training for ADOS-2 typically comprises a 2 day course, costing around £2550

• Training for ADI-R typically takes 3-days, costing approximately £995

What is the Autism Diagnostic Observation Schedule (ADOS-2)?

• A structured observational assessment consisting of various activities that allow observation of “social and communication behaviours related to the diagnosis of pervasive developmental disorders”

• The ADOS can be used to evaluate almost anyone suspected of being autistic across the age range, from children with no speech to adults who are verbally fluent

• ADOS-2 evolved from data and field-trials to align with new DSM-5 diagnostic criteria

• ADOS-2 introduced the ‘toddler module’ for those aged between 12 months to 30 months, not yet using phrased speech

• Administration time is usually between 40-60 minutes

What are the ADOS-2 modules?

1. Toddler Module - 12-30 months, indicating a level of concern

2. Module 1 - Preverbal/Single Words, 31 months and older

3. Module 2 - Phrase Speech, any age

4. Module 3 - Fluent Speech, child/adolescent

5. Module 4 - Fluent Speech, adolescent/adult

• Administrators choose a module based on the individual’s expressive language ability, and in part age

What is the ADOS-2 core test structure?

Each module is comprised of a set of activities designed to elicit behaviours relevant to autism criteria, with activities varying by module but typically assessing :

• Social communication e.g. initiating interaction, responding to name or prompts, sharing enjoyment, facial expression, eye gaze

• Social reciprocity e.g., back and forth conversation, interest in the administrator, emotional sharing, rapport development

• Imagination/creativity/play – pretend play, storytelling, symbolic use of objects

• Restricted/repetitive behaviiours e.g. repetitive speech, atypical sensory interest, rigid behaviours, fixated interests, stereotyped movements

What is the ADOS-2 process from coding to classification?

1.        Administration – administering the ADOS-2 and observing behaviours

2.        Coding – determining item codes

3.        Scoring – converting item codes to ADOS-2 algorithm scores

4.        Classification – establishing a classification of range of concern (toddler module)

What is the coding process of the ADOS-2?

• Observations themselves contain qualitative notes

• Coding requires ratings based on the participant’s behaviour throughout the entire administration

·      0 – does not repeat others’ speech

·      1 – occasional echoing

·      2 – echoing words and phrases regularly, but some spontaneous language, which can be stereotyped

·      3 – speech largely consists of immediate echolalia

How is the ADOS-2 scored?

• The next step is to convert item codes to  ADOS-2 module-specific algorithm scores

• Administrators are asked to then note scores per item and total these for communication, social interaction, then the communication + social interaction total

• There is then a cutoff score assigned for these ready for classification

What are the classification outcomes of the ADOS-2?

The algorithm process and total cutoff scores in Modules 1, 2, 3, 4 leads to an ADOS-2 classification of:

• Autism – interpreted as observed behaviour meets criteria suggestive of autism in this structured setting

• Autism-spectrum – autistic traits are present and clinically relevant but presentation is less pronounced and does not meet full algorithm threshold for autism classification

• Non-spectrum – did not elicit sufficient autism-consistent behaviours to meet algorithm thresholds

What is the Autism Diagnostic Interview-Revised (ADI-R)?

• The ADI-R consists of 93 questions and is conducted as a semi-structured interview with parents or caregivers

• It covers three main areas:

·      Language and communication – evaluating both verbal and non-verbal communication skills

·      Reciprocal social interactions – assessing social behaviours and relationships, including the ability to form peer relationships and respond to social interactions

·      Restricted, repetitive, and stereotyped behaviours and interests – identifying repetitive behaviours, routines, and restricted interests typical in autistic individuals

• Emphasises early developmental history

• Can take up to approximately 3 hours

• Can be used in the assessment of an adult if there is an informant who knew the person well in childhood, but potential issues may arise as recalling events from potentially 20-50 years ago reduces accuracy

• A strength however is that it can generate detailed qualitative data from different stakeholders

What is the global reach of the ADOS-2 and ADI-R?

• The ADOS-2 has been translated, validated, and used worldwide across North America and the UK, Europe (e.g. Germany, Sweden, Greece), and Asia (e.g., China, South Korea, Mandarina)

• There are also studies exploring the use of ADOS-2 in South Africa, though largely in English, and in Middle Eastern Contexts (Arabic, Kurdish, Persian)

• In comparison, the ADI-R is primarily validated in English speaking populations, with less research on the psychometric properties of the ADI-R and their usefulness in diagnosing autism in non-English speaking populations

What are some limitations/critiques of the ADOS-2 and ADI-R?

• ADI-R is dependent on caregiver recall and interpretation; parents/caregivers are not always available

• ADOS-2 provides a snapshot in time only, conducted in clinical context, resulting in low ecological validity

• ADI-R is time-intensive, reducing clinical efficiency and accessibility

• Research indicating ADI-R is less influential in distinguishing ASD vs non-ASD, particularly in adults (Kamp-Becker et al., 2021)

• Both tools may not be sensitive enough to differentiate between autism and complex psychiatric conditions e.g., Maddox et al (2017) found that the ADOS-2 had high rate of false positives among adults with psychosis (who did not have autism)

What did Lebersfeld et a. (2021) find regarding the clinical utility of the ADOS-2 and ADI-R?

• Both tools performed better in respect to Specificity and Sensitivity in controlled research samples compared to real-world clinical population (ADI-R less accurate than ADOS-2)

• ADOS-2 indicated high levels of Sensitivity and Specificity across settings however limited number of clinical-only studies here

• Posited that the specificity of ADOS-2 may be more variable across clinical settings, whereas Sensitivity may remain relatively stable

• Overall recommendation was that both tools need more research solely utilising clinical populations, as clinical population are often more diverse and complex