Autism as a Hierarchy of Impairments

A French Pyramid, worth visiting

Today’s post is not full of complex science.

I am reminded from time to time that I am supposed to be writing a book about translating autism science into practical therapy. To even partially do justice to all the science, things have to get a little complicated, at which point it will inevitably lose many readers.

What is much easier to achieve is to explain what autism is, and is not, and what, if anything, you might want to do about it.

I think you can consider autism as a hierarchy of impairments that together define a particular person’s “autism”.  For example, epilepsy is not just a comorbidity of someone’s autism, it is an integral part of it, and very much so biologically.

All of this is a simplification, but I think it does actually help represent what is currently diagnosed as autism.

Most people diagnosed today with autism are at the lower end of the pyramid/hierarchy, they have impaired social and communication skills to some degree and some of the issues in the level above, maybe some anxiety or ADD or ADHD.

People with severe autism rise through the levels to the summit, perhaps escaping from some elements.

When you then add prevalence to this hierarchy of impairments, you get the graphic below.

Really severe autism is thankfully rare. This was the old autism defined under the diagnostic regime of DSM3.  DSM is an abbreviation of the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association.

In 1994 DSM version 4 introduced Asperger’s as an extension of autism.

We are currently on DSM5 which dropped the term Asperger’s opting for three levels of severity.  Severe autism is called level 3 and mild autism is level 1.  So, a genuine little professor type of Asperger’s would be level 1. Some people are getting diagnosed at intermediate points like 1.5.

Given the fact that the underlying biology is actually extremely complex, involving many hundreds of affected genes, it is perfectly possible to have a person with impaired social skills, who has a high IQ, no physical impairments, but self-injures.

  

Having identified where a person fits in this autism hierarchy, it is then time to see what are the likely consequences.

Having understood the consequences, you can then make plans to mitigate them.

In the case of the person with Asperger’s (DSM5 level 1) there may be very few issues that need to be addressed; but if you ignore the fact they may spend their school years being bullied and feeling excluded, they may fall victim to the 9 times elevated risk of suicide.

Ignoring what appear as minor quirky issues may have major consequences later.

At the summit of the pyramid the big dangers are seizures, self-injury and early death, but not from suicide.

Aggression and self-injury have to be brought under control during childhood, because in adulthood society does not tolerate it.  In most countries there is a lack of appropriate places to house adults with such behaviours and then bad things will inevitably happen.

Some people’s physical impairments fade away, some people never have any, but for some others such issues remain lifelong.

Cognitive dysfunction is part and parcel of DSM3 autism, what now is called Level 3 autism, under DSM5. As we have seen in this blog, some aspects of cognition can be improved using biology.

Personalized Medicine?

When deciding whether to treat a 2 or 3-year-old with autism using personalized medicine it is very important to understand the consequences. If the young child has severe autism (DSM3, or DSM5 level 3) then you know what the likely outcome will be if the child remains untreated. We know that 10-15% of these cases will dramatically improve without any intervention, but 85% will not. Intensive ABA interventions will accelerate skill acquisition in many cases, but it does not address the biological dysfunctions. The end result is a shortened lifespan (on average 40 years), much of it likely in an institution of one kind or another.  This you compare against the risk and cost of personalized medicine.

If you have a 3-year-old with mild autism (DSM5 level 1), the biological issues are quite mild and you will likely achieve great things with simple steps like teaching social skills and finding the right schools (small class sizes and no bullying). If you have very mild autism you may well find the positives outweigh the impairments associated with autism. Great attention to detail, perseverance, reliability and perhaps a high IQ may not make you cool at school, but are highly valued in the "right" workplace.

Not surprisingly, it is mild autism (DSM5 level 1) that gets most of media attention these days. At some point perhaps they will add DSM5 level 0.5 to include even mildly quirky people, but the next target for diagnosis appears to be adult females who could fit DSM5 level 1, but who slipped through the net.  Expect prevalence to continue to increase.