Understanding Adult Autism Spectrum Disorder (ASD) Assessment
Many autistic individuals reach adulthood without receiving a formal diagnosis. Some have learned to “mask” or camouflage their autistic traits, while others may have been misidentified as experiencing anxiety, depression, social difficulties, personality differences, or attention-related challenges.
Our Adult Autism Spectrum Disorder (ASD) Assessment provides a structured evaluation of autistic characteristics, developmental history, social communication patterns, sensory experiences, repetitive behaviours, and compensatory strategies. A comprehensive assessment can help individuals better understand themselves, access appropriate support, improve workplace accommodations, and gain clarity regarding lifelong challenges.
At our clinic, we offer three different types of adult ASD assessment pathways to suit different clinical needs, budgets, and diagnostic requirements.
Option 1: Comprehensive Adult ASD Assessment
Fee: $600 (Inclusive of Psychological Report)
Assessment Process
This assessment consists of:
1. 60-Minute Clinical Interview
- Conducted by a psychologist.
- Reviews developmental history, childhood experiences, social communication patterns, sensory sensitivities, routines, relationships, educational history, occupational functioning, and current concerns.
- Allows for detailed exploration of autism-related traits that may not be captured through questionnaires alone.
2. Online Assessment Battery
The following questionnaires will be emailed to the client for completion:
- RAADS-R (Ritvo Autism Asperger Diagnostic Scale – Revised)
- EQ-40 (Empathy Quotient)
- AQ (Autism Spectrum Quotient)
- CAT-Q (Camouflaging Autistic Traits Questionnaire)
- CATI (Comprehensive Autistic Trait Inventory)
- RBQ-Self (Repetitive Behaviour Questionnaire – Self Report)
- RBQ-Informant (Completed by a family member, partner, or close informant)
Why These Tests Are Included
This battery was selected because adult autism often presents differently from childhood autism. Many adults have developed sophisticated masking and compensation strategies which can obscure autistic characteristics.
The selected measures evaluate:
- Social communication differences
- Empathy and social cognition
- Restricted interests
- Repetitive behaviours
- Sensory experiences
- Camouflaging and masking behaviours
- Developmental traits across the lifespan
- External observations from people who know the individual well
The RAADS-R has demonstrated good psychometric validity and reliability in identifying autistic traits in adults and remains one of the most widely used adult autism screening instruments internationally.
The CAT-Q is particularly valuable because research has shown that many autistic adults consciously or unconsciously camouflage autistic behaviours, leading to delayed diagnosis, especially among women and high-functioning adults.
Suitable For
This option is ideal for:
- Adults exploring whether they may be autistic
- Individuals seeking clarification regarding lifelong social or sensory difficulties
- Working professionals
- University students
- Individuals who suspect they may be masking autistic traits
- Those wanting a comprehensive assessment without the higher cost of ADOS-2 administration
Benefits
- Comprehensive multi-dimensional assessment
- Specifically designed for adult presentations of autism
- Sensitive to masking and camouflaging
- Includes collateral informant data
- Cost-effective diagnostic pathway
- Suitable for most adults seeking diagnostic clarification
Option 2: Extended Comprehensive Adult ASD Assessment
Fee: $1,200 (Inclusive of Psychological Report)
Assessment Process
This assessment includes everything contained in Option 1, plus:
Autism Diagnostic Interview – Revised (ADI-R)
The ADI-R is a structured developmental interview conducted with a parent, caregiver, sibling, spouse, or someone familiar with the individual’s developmental history.
The interview explores:
- Early childhood development
- Language development
- Social interaction patterns
- Communication difficulties
- Restricted and repetitive behaviours
- Developmental milestones
- Historical evidence of autism symptoms
The ADI-R typically requires 1–2 hours to complete and is regarded internationally as one of the most established diagnostic instruments for autism assessment.
How This Option Differs From Option 1
While Option 1 focuses primarily on current functioning and self-report measures, Option 2 incorporates a detailed developmental history component.
This is important because autism is a neurodevelopmental condition that begins in childhood. The ADI-R allows clinicians to evaluate whether autistic characteristics were present throughout development rather than emerging later in life.
Suitable For
This option is recommended for:
- Individuals seeking greater diagnostic confidence
- Cases where developmental history is available
- Adults requiring more detailed evidence for workplace or educational accommodations
- Complex presentations where other conditions may overlap with autism
- Clients seeking a more thorough developmental investigation
Benefits
- All benefits of Option 1
- More detailed developmental analysis
- Stronger historical evidence
- Improved diagnostic confidence
- Useful for complex diagnostic cases
- Provides richer clinical information for recommendations and intervention planning
Option 3: Gold Standard Autism Diagnostic Assessment
Fee: $3,800 (Inclusive of Psychological Report)
Assessment Process
This assessment includes:
Autism Diagnostic Interview – Revised (ADI-R)
A structured developmental interview with an informant familiar with the individual’s childhood and developmental history.
Autism Diagnostic Observation Schedule – Second Edition (ADOS-2)
The ADOS-2 is a semi-structured clinician-administered assessment involving direct observation of communication, social interaction, emotional reciprocity, imagination, conversational style, and restricted or repetitive behaviours.
The ADOS-2 allows clinicians to directly observe behaviours associated with autism in real-time rather than relying solely on self-report questionnaires. It is widely regarded as one of the most important observational assessment tools for autism diagnosis.
Why ADOS-2 and ADI-R Are Considered the Traditional Gold Standard
For decades, the combination of ADI-R and ADOS-2 has been regarded internationally as the gold-standard approach for autism diagnosis.
The ADI-R provides developmental history, while the ADOS-2 provides direct behavioural observation. Together, they assess both historical and current manifestations of autism. Clinical guidelines frequently identify both instruments as key diagnostic tools for autism assessment.
Research demonstrates strong diagnostic accuracy for the ADOS-2, with reported sensitivity generally ranging from approximately 89% to 92% and specificity ranging from approximately 81% to 85% across studies.
Suitable For
This option is recommended for:
- Complex diagnostic presentations
- Medico-legal assessments
- High-stakes educational accommodation requests
- Formal disability documentation
- Individuals requiring the most rigorous diagnostic process available
- Cases involving significant diagnostic uncertainty
Benefits
- Traditional gold-standard assessment methodology
- Direct clinician observation
- Comprehensive developmental investigation
- Highest level of diagnostic rigour
- Widely recognised internationally
- Particularly useful for complex or high-stakes cases
Comparison of Assessment Options
| Feature | Option 1 | Option 2 | Option 3 |
|---|---|---|---|
| Clinical Interview | ✓ | ✓ | ✓ |
| RAADS-R | ✓ | ✓ | – |
| AQ | ✓ | ✓ | – |
| EQ-40 | ✓ | ✓ | – |
| CAT-Q | ✓ | ✓ | – |
| CATI | ✓ | ✓ | – |
| RBQ-Self | ✓ | ✓ | – |
| RBQ-Informant | ✓ | ✓ | – |
| ADI-R | – | ✓ | ✓ |
| ADOS-2 | – | – | ✓ |
| Developmental History Analysis | Moderate | Extensive | Extensive |
| Direct Behavioural Observation | – | – | ✓ |
| Diagnostic Rigour | High | Very High | Highest |
| Cost | $600 | $1,200 | $3,800 |
Which Assessment Should I Choose?
Option 1 is suitable for most adults seeking a thorough and evidence-based autism assessment at an affordable cost.
Option 2 is recommended for individuals who have access to developmental informants and would like a deeper developmental analysis to strengthen diagnostic confidence.
Option 3 is the traditional gold-standard pathway and is generally recommended when the highest level of diagnostic rigour, direct behavioural observation, or formal documentation is required.
References
Ritvo, R. A., et al. (2011). The Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R): A scale to assist the diagnosis of Autism Spectrum Disorder in adults. Journal of Autism and Developmental Disorders.
Andersen, L. M. J., et al. (2011). Validation of the RAADS-R in adult ASD assessment. Curnow, E., et al. (2023). Diagnostic assessment of autism in adults.
Lebersfeld, J. B., et al. (2021). Systematic review and meta-analysis of the clinical utility of ADOS-2 and ADI-R.
Lord, C., Rutter, M., & Le Couteur, A. Autism Diagnostic Interview-Revised (ADI-R).
Autism Diagnostic Observation Schedule-2 (ADOS-2) clinical literature.