Biology of profound and non-profound autism

Scientists have spent a lot of time trying to understand the biology of autism, unfortunately in the past, scientific studies had everyone with autism lumped together in one group and there are so many differences between people with a diagnosis that any features of the diagnosis itself were hard to detect. In the past, researchers grouped those who are cognitively abled with those who have average or superior intellectual disability, those who are able to express themselves verbally with those who cannot, and those who need 24-hour care with those who can live independently. This week, researchers changed that pattern of lumping all the autisms together by using profound autism as a subgroup and as a way to determine differences across autism subgroups. Researchers at @UCSD examined the cell sizes and the brain sizes of individuals with profound autism and compared them to those with non-profound autism. They found the larger the brain cell, the larger the brain size in different areas, and the more profound the autism. There were differences between profound autism, non-profound autism and typically developing controls. This is just a first step in using different classifications of behavior to understand the neurobiology of ASD and link brain function to autism behaviors, leading to more specific support for those across the spectrum.

https://molecularautism.biomedcentral.com/articles/10.1186/s13229-024-00602-8#Sec26

Are new ICD-11 criteria for an autism diagnosis too vague?

In the last version of the Diagnostic and Statistical Manual, the different subtypes of autism were folded into one label: autism spectrum disorder. A similar revision is being made around the International Classification of Diseases, the system the WHO uses across the world to describe autism and provide appropriate reimbursements for services and supports. In this version, the ICD-11, a combination of 300 different presentations of autism are described. A diagnosis can be made if 1 feature of social-communication and 1 feature of repetitive behaviors are documented, with an onset of any time in life. This is causing a lot of confusion in the community, because since the presentations are not specific to autism, it is difficult to provide an accurate diagnosis using the ICD-11. This week we talk to German psychiatrist Inge Kamp-Becker, MD, who outlines what the changes are, and how misdiagnosis can be made and what those consequences might be. Her summary is linked below.

https://www.nature.com/articles/s41380-023-02354-y

Speak now

Those who are minimally verbal or non speaking represent about 25% of those with an autism diagnosis, yet there is really a lack of effective interventions for this group of autistic individuals. It used to be that everyone who was non-speaking was thought to have minimal ability to understand language, since understanding and speaking are so linked in development. However, group at Boston University studied the largest group of non-speaking autistic individuals so far and discovered that about 25% of them understand more language than they can speak, although this ability is still far lower than those who are neurotypical. The other 75% understand about as much as they can communicate verbally. This indicates that in some cases, the ability to understand words and their meaning exceeds the ability to communicate those ideas verbally. Surprise surprise, just like everything autism – there are differences across the spectrum. Thanks to Yanru Chen at Boston University for explaining the study to us.

https://onlinelibrary.wiley.com/doi/10.1002/aur.3079

The ASF Year End Review of Science

Just three days before 2024, ASF provides a summary of the the highlights of scientific discoveries and how they have translated into tools families can use. They include ways to speed up diagnosis and reduce waitlists, study of the brains in females and clinical recommendations for helping autistic females at birth, evidence of better practices around intervention and supports, and a review of the numbers of people who have a diagnosis. It isn’t comprehensive and if something was missed, our apologies, but the summary is 20 minutes.

You can read the text here: https://autismsciencefoundation.org/2023-year-end-review/

How many people can be described as having “profound autism”?

Quick answer: 26.7%. But what is “profound autism” and why is this label necessary? Have the rates of profound autism changed over time? How many do not have profound autism and are their needs different and how? Listen to this week’s ASF podcast and read the paper here: https://autismsciencefoundation.org/wp-content/uploads/2023/04/CDC-Profound-Autism-Statistics_ASF-Copy.pdf