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The wide-angled lens of autism

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‘How can one condition be so variable?’

That is perhaps the most common question my GP colleagues ask me about autism.
 
Take, for example, an articulate female academic and a non-verbal man who needs constant care. These people couldn’t appear more different, yet they share the same diagnosis. They’re both ‘on the spectrum’. How can this be so?
 
What we need to do is look past their obvious differences and see what they have in common.
 
When the American Psychiatric Association was reviewing the diagnostic criteria for autism in the Diagnostic and Statistical Manual of Mental Disorders (DSM–5), they separated into two main camps, referred to as ‘splitters’ and ‘clumpers’.
 
Splitters were in favour of retaining several different diagnoses, as in the DSM–IV.
 
However, the clumpers won the day. Autistic disorder, Asperger’s disorder, and (the clunkily-named) pervasive developmental disorder not otherwise specified (PDD-NOS) were all subsumed under a single label of autism spectrum disorder (ASD).
 
Under DSM–5, an ASD diagnosis comes with a level of severity from 1–3, depending on how much support that person is likely to need.
 
These changes were considered controversial in 2013, but six years down the track there is growing acceptance that the DSM–5 criteria are probably an improvement on earlier versions.
 
So, what do all people with ASD have in common under DSM–5? Essentially, they must present with two overarching behaviours:

• Persistent deficits in social communication and social interaction
• Restricted, repetitive patterns of behaviour, interests, or activities

DSM–5 goes on to describe the many ways these behaviours might present. These range from, for example, ‘difficulties making friends’ to ‘a complete absence in interest’ in other people; from obsessive interests to persistent, intrusive motor movements such as flapping or finger-waving. In this way, it accounts for all levels of symptom severity.
 
It is important to note that it’s not enough to have a few autistic traits to qualify as ASD. For a person to receive a diagnosis, these behaviours must be negatively impacting on function – the D in ASD. People with ASD are, by definition, not doing as well as they should be. 
 
Another important factor is co-diagnoses, which the DSM–5 specifically takes into consideration. In particular, an individual with ASD and an intellectual disability will have more severe symptoms than someone with ASD and a normal IQ. 
 
A person with ASD and attention deficit hyperactivity disorder (ADHD) will have added issues associated with impulsivity and inattention, whereas someone with ASD and severe anxiety may be more impacted by the second diagnosis. Language disability also commonly occurs alongside ASD, affecting speech development as well.
 
Finally, gender differences are increasingly being recognised. Girls with ASD seem better able to compensate for their social difficulties (called ‘masking’) and have less obvious restricted interests. Many females are not diagnosed until adulthood, when they present with conditions such as anxiety, depression, eating disorders and self-harm.
 
When we take all of these factors into consideration, it’s easier to reach the common conclusion:
 
‘If you’ve met one person with autism, you’ve met one person with autism.’

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ASD autism autism spectrum disorder World Autism Awareness Day

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