The changes of autism through time: are females finally recognised?

Autism hasn’t always been what we know it as today. Even now we still revise and revisit the criteria of diagnosis due to developments of research within the field. A specific handbook used by professionals to diagnose autism is DSM (Diagnostic and Statistical Manual of Mental Disorders) [2]. There have been revisions of the DSM due to changes in research outputs and specialists’ opinions. As a result, autism has meant different things at different points throughout history. 

1943- Kanner 

Autism was initially described by a psychiatrist and physician called Kanner in 1943 [1]. He produced the first account of autism in “Autistic disturbances of affective contact” in the journal “The nervous Child” – link. The article described case studies of eleven children who portrayed classic signs of autism, with many of the children often displaying extreme intelligence, and some having unique talents. This paper was descriptive, producing further questions surrounding the underpinnings of autism- nature vs nurture.

Initially, Kanner believed autism may in fact have underpinnings in biology. However , in  1949 his view shifted, leading to a belief that autism may in fact be a psychological disorder, speculating that mothers may be the cause of such difficulties, rather than other biological reasons such as genetics [1].

1952- DSM-II definition of autism 

Kanner’s view on the causes of autism may have influenced the second edition of the DSM (DSM-II), which described autism as a psychiatric condition which was a form of child schizophrenia. 

1950-1960- Bettelheim  

Though the description in the DSM-II was leaning towards a psychiatric cause rather than biological, this was further alluded to by Bettelheim, a psychologist influenced by Freudian psychology [3], whereby childhood experiences influenced our adult lives, shaping our personality. He believed that autism was caused by the unemotional nature of certain mothers, coining the term “refrigerator mothers”, further suggesting the psychiatric nature of autism.  

1960-1980 – DSM-III: moving towards the spectrum of autism

However, even though Bettelheim and Kanner deemed autism to be psychiatric, other research began to shift to the potential biological nature of autism. This shift toward the biological nature of autism was based on work published in 1964 by Bernard Rimland [3-4], suggesting that autism was in fact a neurodevelopmental condition rather than a psychiatric condition. This was reflected in DSM-III (1980) describing autism as a “pervasive developmental disorder” [2], importantly suggesting its distinction from schizophrenia. It defined certain essential features of autism: 

1. Limited interest in other people 
2. Impairment of communication (socially) 
3. Unique responses to the environment around them 

Interestingly, all of these symptoms must have been present in early life [2]. 

1987- revised DSM-III: moving towards the spectrum of autism 

Though the word spectrum was not explicitly used, the revised DSM-III acknowledged that there was a range of severity within autism, thus the concept of autism forever changed. DSM-III provided a diagnosis called pervasive developmental disorder- not otherwise specified (PDD-NOS), which suggested the possibility of milder features within autism, this was further suggested by the removal of the requirement for onset of traits in early life. 

This change provided a new outlook on what autism was, suggesting it was not a single condition and that there were different levels of severity within the “umbrella” term.  

The revised DSM-III also provided an updated manual of features [5], 16 features within the three previously mentioned domains, of which 8 had to be met to reach a diagnosis. This created more specificity in diagnosis [1]. 

1990-2000- DSM-IV: The first description of autism as a spectrum 

Within DSM-IV there was the first mention of autism being a spectrum of disorders. Within the DSM-IV one could be diagnosed with:

1. Autism 

2. PDD-NOS 

3. Asperger’s Disorder  

4. Childhood disintegrative disorder (CDD) 

5. Rett’s syndrome 

This breaking down of diagnosis into subgroups began to reflect the different phenotypes seen within autism. Interestingly, within DSM-IV there is a mention that males are more likely to have autism, with suggestions that females may in fact be more likely to have Rett’s syndrome, accompanied with severe intellectual disability. However, there was no mention of different presentations of males and females, thus, excluding females potentially from diagnosis. 

This exclusion of females didn’t just start with the DSM-IV, though Kanner described three females within his paper- “Autistic disturbances of affective contact”, the idea that males are more likely to have autism has stuck, potentially causing biases in the DSM criteria- read The gender bias of Autism.  

2003- the human genome project 

Since the human genome project completed in 2003, there was a race to identify genes that could contribute to autism, further proving the biological underpinnings of autism.  However, using GWAS (Genome Wide Association Studies- an approach used to see if there are specific genetic variants that may be causing a specific disease, involved scanning the genome of thousands of people to look for differences in the genome that could contribute to a disease) hundreds of candidates were found, but when scrutinized none were directly linked to non-syndromic* autism. The lack of support for a single cause of autism it further pushed autism towards the idea that it could in fact be a spectrum.

2013- DSM-5: the beginning of Autism Spectrum Disorder (ASD)

This is the most current diagnosis criteria of diagnosis for autism using DSM- link, however, this new manual for diagnosis removed PDD-NOS and Asperger’s Disorder as individual diagnoses and instead put them into a new category called autism spectrum disorder(ASD), the aim was to acknowledge the variability within autism[6], as prior to this there were numerous subcategories which made it hard for consistent and accurate diagnosis.

The term Asperger’s however, has stuck due to its popularity within the autistic community. It technically is now part of ASD, though there is still some confusion surrounding the terms. Asperger’s has been compared to high-functioning autism, which describes “milder” autism within ASD. 

Furthermore, Rett’s syndrome was removed due to the severe autistic traits only presenting in a narrow window of a patient’s life and it’s a distinct condition compared to the others seen within the DSM.  

DSM-5: Mention of female phenotypes? 

Though there is still a gender ratio for female to male diagnosis, little was mentioned to address this difference within DSM-5, this may be due to research on female presentation of autism being in its infancy thus preventing DSM-5 from expanding their diagnostic criteria. 

Though the DSM-5 did not provide direct examples of the different presentations of autism it did acknowledge that there may be sex differences and diagnostic issues. 

‘In clinic samples females tend to be more likely to show accompanying intellectual disability, which suggests that girls without accompanying intellectual disability or language delays may go unrecognized, perhaps because of subtler manifestation of social and communication difficulties.’ 

DSM-5

Though this does not help the diagnosis of women currently, due to the long standing biases seen throughout history and limited knowledge on how women may present, there is hope that within the next edition of the DSM there will have been enough research to challenge this, allowing for better diagnosis in women and girls. 

* Syndromic and Non-syndromic Autism 

Two types of autism (to confuse the situation even more) syndromic is usually a single gene mutation or chromosomal abnormalities causing neurological conditions, of which some traits present as autism, an example of this is Fragile X syndrome. However, non-syndromic autism, accounting for majority of cases [7] and what we are referring to here, has no true cause defined, but it has been suggested that it involves the effect of many genes all with small changes in them. 

Written by- Georgia Cronshaw

References:

1. Zeldovich L. The evolution of ‘autism’ as a diagnosis, explained [Internet]. Spectrum. Autism Research News. 2018 [cited 2021Feb15].. Available from: https://www.spectrumnews.org/news/evolution-autism-diagnosis-explained/
2. Regier DA, Kuhl EA, Kupfer DJ. The DSM-5: Classification and criteria changes. World Psychiatry. 2013 Jun;12(2):92-8.
3. Blakemore E. Psychologists Once Blamed ‘Refrigerator Moms’ For Their Kids’ Autism [Internet]. HISTORY. 2018 [cited 2021Feb15]. Available from: https://www.history.com/news/autism-theory-refrigerator-mother
4. Rimland B. Infantile Autism: The Syndrome and Its Implications for a Neural Theory of Behavior. London : Methuen; 1964. 282 p.
5. Volkmar FR, Bregman J, Cohen DJ, Cicchetti DV. DSM-III and DSM-III-R diagnoses of autism. Am J Psychiatry. 1988 Nov;145(11):1404-8
6. Happe F. Why fold Asperger syndrome into autism spectrum disorder in the DSM-5?: Spectrum: Autism Research News [Internet]. Spectrum. 2011 [cited 2021Feb15]. Available from: https://www.spectrumnews.org/opinion/viewpoint/why-fold-asperger-syndrome-into-autism-spectrum-disorder-in-the-dsm-5/ 
7. Bury LA, Wynshaw-Boris A. Modeling Non-Syndromic Autism with Human-Induced Pluripotent Stem Cells. Neuropsychopharmacology. 2018 Jan;43(1):219–20.