Exploding Myths: The Use of the ADOS and Diagnosis of Autism  by Dr Michelle Garnett & Prof Tony Attwood

Exploding Myths: The Use of the ADOS and Diagnosis of Autism by Dr Michelle Garnett & Prof Tony Attwood

In the lead up to our next Event, Masterclass: Diagnostic Assessment and Intervention with Adults with Autism we have often been asked: Will the full day training on diagnostic assessment provide a thorough training in the Autistic Diagnostic Observational Schedule, Second Edition (known at the ADOS)? At  Minds & Hearts, we are increasingly asked by professionals to provide an ADOS to determine if the person is on the autism spectrum.

Certainly, for many years the ‘gold standard’ in the diagnosis of autism was considered to be the combination of two instruments, the Autistic Diagnostic Interview – Revised (ADI-R), and the ADOS. The combination was considered to be the research standard, but only for classic autism, and only for definitions of autism in previous editions of the diagnostic manuals.

Of course, we do not expect that everyone has the time to scour the literature, to read the manuals for the diagnostic instruments available, and to know the current ‘gold standard’ for autism. However, we are lucky to be in the position, as clinical psychologists who have specialised in autism over the past 30 and 50 years respectively, to be able to keep a finger on the diagnostic pulse of autism.

It may surprise you to know that, because the diagnosis is subjective, that is, there no biological markers for autism that we know of, the current ‘gold standard’ is a clinician assigned diagnosis, as provided by experienced clinicians. There is no tool that can diagnose autism. An experienced clinician keeps abreast of the current diagnostic and other tools available, and chooses the best tools, based on the referral information, the age, the differential diagnoses, and the gender of the person to be assessed.

Some presentations of autism are more subtle, for example, many adults who are verbal and have at least average intelligence, especially if they use camouflaging as a coping strategy, have a subtle presentation of autism. When this is the case, the ADOS may be used as part of a diagnostic assessment, but often would not be the first choice.

Diagnostic assessment tools are evaluated using a standardisation sample, which is a group of people chosen because they represent the people that the tool will be used to assess. The group needs to be representative, and large enough to give statistical weight to the results. In the development of Module 4, the part of the ADOS that would be used to assess a verbal adult of at least average intelligence, the sample was only thirty people, and of this sample only five were female. The algorithms for determining if the person has autism are based on previous definitions of autism and the predictive validity of the ADOS was only approximately 50%.

A recent study (Langmann, et al, 2017) examined the ADOS, Module 4, in a sample of 356 sample, 12 to 68-year-olds. Results showed that the ADOS had low diagnostic accuracy for females, older individuals and individuals with personality disorders or high intellectual ability. 

We strongly encourage diagnosticians seeking to increase their skill in the assessment of adults who may have autism, to seek training in what data to collect, i.e. what to look for, and the best methods to collect the data. We recommend that before seeking specific training see many adults who are, and who are not, on the autism spectrum. Once trained in the diagnostic assessment for adults, we highly recommend receiving clinical supervision for the first few cases.

We encourage clinical psychologists, GPs with an interest in autism and adult psychiatrists to seek training in the diagnosis of autism, in all its forms and variations across age, gender, verbal ability and IQ. For example, t is currently the case that adult women have seen an average of four clinicians before they receive an accurate diagnosis of autism. In the meantime, they have been mislabelled, received misinformation about their conditions, and have missed out on accurate and appropriate interventions to assist them with their self-understanding and overall mental health.


Langmann et al (2017). Research in Autism Spectrum Disorders 34 pp 34-43

You will also receive:

  • Access to the presentation for 60 days following the live event
  • A Live Chat Room for Q&A with Tony & Michelle throughout the day
  • Downloadable Handouts to complement the course
  • Certificate of Attendance


Course materials are presented, using a combination of didactic teaching, case studies, and question time. Each day is a stand-alone workshop, and participants may choose to choose either one or both workshops.

Participants will learn how to conduct a diagnostic assessment for an adult or older adolescent with autism, including measurement of comorbidity, differential diagnosis, and use of psychometric assessment.

Participants will learn common presentations and challenges that adults with autism face, reasons for the challenges and strategies to accommodate the characteristics of autism. Emotion management, relationship development, workplace issues, substance use, forensic issues, personality disorders, sexuality, psychosis, and gender identity will be discussed.