Are there 'millions missing' when it comes to adult autism?

Enhancing Adult Autism Diagnostic Pathways: The Role of Clinical Triage in Efficient Service Provision https://www.mdpi.com/2077-0383/14/9/2933

The Adamou paper sees the important peer-reviewed light of day having spent some time as a preprint.

It took 60 people referred to the "specialist adult Autism Service in West Yorkshire, UK, from November 2021 to August 2022" with suspected autism. Triage teams assessed them for autism including information from multiple sources and concluded that: "No clinical diagnoses of ASD were confirmed in the assessed sample."

This is an important paper requiring further follow-up. It tells us that there are perfectly good models of autism assessment triage that are available to healthcare systems such as the UK National Health Service (NHS) which can be used to work through the massive backlog of people awaiting an autism assessment (mostly children but adults as well). 

It also tells us that the stories that there are 'millions missing' in terms of adults with undiagnosed autism are probably not all accurate. Indeed, other evidence has come to a similar conclusions based on 'actual reporting' rather than 'we think there may be many undiagnosed people' estimated reporting: Characteristics and primary care experiences of people who self-report as autistic: a probability sample survey of adults registered with primary care services in England https://pubmed.ncbi.nlm.nih.gov/39277196/ "A total of 4481 of the 623 157 survey participants included in the analysis self-reported autism, yielding a weighted proportion estimate of 1.41% (95% CI 1.35% to 1.46%)." 

You don't need to be a rocket scientist to see the disparity between childhood autism diagnoses (~5%) and adult diagnoses (~1%) to see where the growth in numbers is coming from. Indeed, if one assumes that autism may be either prodromal for some and/or indeed, not universally lifelong for some, those stats make even more sense...