Autism Is Complex, Not Mechanistic
A Response to Rødgaard et al.’s Meta-analysis & Others
A recently published article claims that the differences between individuals with autism and those without autism have decreased over time. Over the past few weeks, it has been interesting to observe the various arguments and agendas about autism that the article is being used as “evidence for.” Most (actually all that I have read so far) of the arguments and conclusions drawn from the study are far reaching and cannot actually be ascertained from it. The discussions have also spotlighted increasing prevalence rates and the continued debate on how autism is defined and diagnosed. I decided to attempt an analysis of the article and also provide additional perspectives and dialogue as what we choose to pay attention to, study, and report on matters.
First, let’s focus on the article itself to understand what exactly we can take away from it. The article is a meta-analysis of 11 meta-analyses; this means that it combined data from other articles that had already combined data from other articles. Put differently, the study used the findings from the 11 articles that had already taken their findings from hundreds of other articles. This has become a popular method for identifying commonalities from a large body of research; however, when data is used and combined in this way, we only get part of the story. And, we only get the part that the researchers or authors want us to get. Although a meta-analysis uses straightforward statistical calculations to draw conclusions, many of the decisions made in creating the study are subjective. This means that the researchers make decisions regarding various components that have a significant impact on the conclusions.
The 11 studies included in the meta-analysis were only included if they used “proper outcome metrics” and were excluded if they used other things that did not allow them to be meaningfully compared to the rest of the studies. Therefore, the meta-analysis only used other studies that were convenient and shared commonalities.
The resulting articles were all meta-analyses from the past 6 years that looked at only 7 constructs within 3 domains: social (emotion recognition and theory of mind), executive (cognitive flexibility, planning, and inhibition), and neurologic (event-related potential P3b and brain size). And, the conclusion was that differences have decreased over the years for 5 of the 7 constructs- emotion recognition, theory of mind, planning, event-related potential, and brain size.
What this article does is suggest that the differences in specific scientific constructs that have been previously measured between individuals with autism and controls have decreased over time. Put more simply, the article only tells us that the profiles of those diagnosed with autism have changed over time.
What the article does not do is provide a full picture of autism (or even close to it). The article did not look at all studies or constructs associated with autism that may show more differences. The authors make a short comment about it in the limitations section stating, “The constructs studied did not cover the entire range of domains for which autistic differences have been found in cognitive neuroscience.” This means that differences in other constructs may actually be more stable and consistent with the autism profile (the study itself actually found at least two of them).
The findings do not imply causation or tell us why the results are what they are. Although the authors hypothesize reasons, these are guesses at best. Before getting into the implications and conclusions drawn from the study, it is important to identify the subtle assumptions made in the article that in turn influence the conclusions. At the most basic level, the article is focusing on a scientific process or the “ability of the scientific community to detect neurocognitive and neurologic differences between autistics and control samples.” The goal of the research as stated a couple different times was, “to build and advance mechanistic models of the condition.” Put in another way, the underlying agenda of the researchers is to find specific biological processes involved in autism. Although some comparisons to schizophrenia are made in the study, what is not mentioned in the article is that we have yet to find “scientific proof” or specific biological processes for any diagnosis. This is why a brain scan, blood test, or psychological or neuropsychological test cannot provide a definite diagnosis. Although we do have processes that help us to better assess and understand people, all mental health diagnoses are subjective (see a previous blog for a deeper discussion).
The article also does not tell us that diagnostic practices have resulted in increased prevalence rates. However, the authors do suggest that diagnostic criteria and “less stringent case ascertainment” have resulted in a “blurring of the distinction between autistic traits and autism.” They warn that this blurring of the line could potentially make it more difficult to study. Various corresponding articles have taken it a step further and use the study to draw conclusions around faulty diagnostic practices and claims that autism has become a “catch-all” diagnosis and “too broad of a category to hold meaning.” In one article, Dr. Mottron (one of the researchers and authors) stated, “Our study shows that changes in diagnostic practices, which have led to a false increase in prevalence, are what's fueling theories that autism doesn't really exist.” If you have read above, you now know that this is a complete fallacy but does show the motivation and agenda behind the research that directly impacts the outcomes, results, and publicity.
What the research and complementary articles forget to do is consider other reasons for the findings. Could it be that we are actually seeing and including more autistic people instead of the small subset that it once consisted of (mostly white males)? And that, as we learn more about autism, what we thought we knew (or that past scientific research has shown) is no longer true or only gives us part of the picture? It does not surprise me that how we have thought about and diagnosed autism in the past has changed. The diagnosis was originally created by a psychiatrist to describe a group of patients with schizophrenia diagnoses who tended to detach from interactions. The understanding of autism has come a long way since that description. At the most basic level, autism is not a “psychiatric condition,” as described in the article, but is considered a neurodevelopmental process that influences people differently. A diagnosis is a medical concept meant for a quick fix or intervention, which autism also is not. The psychiatric and scientific community have a hard time wrapping their head around the diagnosis because there is no “pill” or “intervention” for autism. Although many are using the findings to imply that people are getting diagnosed with autism who actually aren’t autistic, it is also true that diagnostic practices are not diagnosing people as autistic who actually are, especially females and adults.
The results of the study suggest that the profiles of individuals diagnosed with autism have changed over the years. This was not groundbreaking and did not come as a surprise to me. For example, we have new information about what may have been referred to as “social deficits” in the past. Specifically, autistics do just as well as, and sometimes better than, non-autistic people on tests that measure Theory of Mind (one of the constructs from the study). Research also suggests that social difficulties actually go both ways and refers to it as a “double empathy problem” in which neither the autistic or non-autistic person have a social ‘deficit’ but that both have difficultly interpreting the gestures, tone or pace of the other’s conversation. The ability or lack of ability to make eye contact is also no longer thought of as a good indicator or autism by itself as there are plenty of autistic people who can make eye contact or have learned to do so and plenty of non-autistic people who do not make eye contact. Executive functioning difficulties are part of various other neurodevelopmental and mental health diagnoses (almost all of them) and are not unique to autism. As already discussed above, autism does not have distinct neurological markers and also has nothing to do with intellectual abilities. So, if we only consider these select constructs (like the meta-analysis did) that do not apply to all or only autistic individuals, it is not surprising that the gap appears to be getting smaller.
Autism is not a specific, constant set of charactersitsics within each person and being autistic affects people in different ways. Every autistic person has different traits that vary depending on time, place, and circumstance. Despite the name, what makes someone autistic is not a point on a single, linear spectrum. In fact, one of the features of autism is an uneven profile of abilities and the diagnostic criteria only require checking some of the boxes, not all. Diagnosing autism also involves more than meets the eye and can be observed behaviorally. There are also many co-occurring differences and diagnosis that can influence symptom presentation such as an intellectual disability, learning disabilities, language disorders, dyspraxia, alexithymia, seizures, and medical issues. Although these may commonly occur with autism and often get lumped into the diagnosis, they are not autism.
What many researchers and clinicians want is for an easy and straightforward classification system and some even suggest using labels to differentiate between “high” and “low” functioning. However, as described above, autism is not a specific set of symptoms that collectively worsen or improve as you move from one end the spectrum to the other. Functioning labels are not only inaccurate, but are also ambiguous because everyone has a different definition of “functioning.” Functioning labels are not helpful, and can actually be harmful, when used to describe an autistic person. Recently, researchers argued that ‘high functioning autism’ should be abandoned in research and clinical practice. What functioning labels represent is how much the person does or does not appear to be outwardly autistic based on observable behavioral characteristics but does not account for hidden or invisible difficulties. This is especially concerning as many individuals have learned to hide or mask their symptoms to fit in or appear “less autistic.” And masking comes at a price that includes such side-effects as significant anxiety, depression, eating disorders, self-harm, and suicide, especially in females.
Autism is a collection of related characteristics that are intertwined and impossible to neatly operationalize and pick apart. Instead of trying to uncover or create a scientific model that “figures it out” so that we can treat and fix it, researchers could benefit by investing energy in things that really matter for autistic people. Research should focus more on specific symptoms or characteristics verses an actual category or diagnosis. If a categorical or dimensional approach is used, instead of functioning labels, the DSM levels of support needs and clinical specifiers can be used. And, it is also important to acknowledge other diagnoses that can influence symptoms. Even when using a dimensional process, there will still be heterogeneity as all the individual dimensions cannot be accounted for.
The solution is not to make it so that only people with the most visible symptoms get diagnosed and receive predetermined services and supports, but about understanding individual profiles so that everyone gets the support they need. Finding a one-size-fits-all approach is not the way to go. The diagnosis does not need an intervention. Although more autistic people are expressing their pride and are sharing themselves with the world, stigma, discrimination, marginalization, oppression, and bullying and abuse are still fiercely present. Striving to better understand, describe, respect, and celebrate a person’s neurodiversity does not water down the fact that differences can create some real difficulties and disabilities. And, one does not get to decide who is disabled and who is not by trying to place people in non-existent and improbable scientific categories.