About the DSM and autism spectrum disorder diagnosis
When diagnosing autism, professionals like paediatricians, psychiatrists, psychologists and speech pathologists use the Diagnostic and statistical manual of mental disorders (5th edition), or DSM-5, produced by the American Psychiatric Association.
The DSM-5 lists the signs and symptoms of autism and states how many of these must be present to confirm a diagnosis of autism spectrum disorder. The DSM-5 refers to ‘signs and symptoms’, but this article talks about ‘signs and characteristics’.
To find out whether a child has autism signs and characteristics and meets DSM-5 criteria, professionals also need to do extra tests. These tests are called a diagnostic assessment.
DSM-5 and autism diagnosis
The DSM-5 replaced the old manual (DSM-IV) in May 2013.
The DSM-5 made some key changes to autism diagnosis. There’s now a single diagnosis of autism spectrum disorder that replaces the different subcategories that were used previously – autistic disorder, Asperger’s disorder and pervasive developmental disorder – not otherwise specified (PDD-NOS).
There’s also a separate diagnosis of social communication disorder (SCD).
DSM-5 criteria for autism diagnosis
Professionals diagnose autism spectrum disorder on the basis of difficulties in two areas – ‘social-communication’, and ‘restricted, repetitive and/or sensory behaviours or interests’.
To be diagnosed with ASD, children must:
- have difficulties in both areas
- have had characteristics from early childhood, even if these aren’t picked up until later in childhood.
Difficulties in social communication
To be diagnosed with autism spectrum disorder, children must have difficulties in the area of social communication.
Signs of difficulties in this area include:
- rarely using language to communicate with other people
- not speaking at all
- rarely responding when spoken to
- not sharing interests or achievements with parents
- rarely using or understanding gestures like pointing or waving
- using only limited facial expressions to communicate
- not showing an interest in friends or having difficulties making friends
- rarely engaging in imaginative play.
Restricted, repetitive, and sensory behaviour or interests
Children must have difficulties in the area of restricted, repetitive and/or sensory behaviours or interests to be diagnosed with autism spectrum disorder.
Signs of difficulties in this area include:
- lining up toys in a particular way over and over again
- frequently flicking switches or spinning objects
- speaking in a repetitive way
- having very narrow or intense interests
- needing things to always happen in the same way
- having trouble with changes to their schedule, or changing from one activity to another
- showing signs of sensory sensitivities like becoming distressed by everyday sounds like hand dryers, not liking the feel of clothes labels, or licking or sniffing objects.
An autism spectrum disorder diagnosis includes a support level. This is used to show how much support children need:
- Level 1 – children need support.
- Level 2 – children need substantial support.
- Level 3 – children need very substantial support.
These levels reflect the fact that some people have autism characteristics that only mildly affect their everyday lives. Others have characteristics that severely affect their everyday lives.
The diagnosis indicates support levels for each area of difficulty. This means that children might have different support levels for their social-communication skills compared to their restricted, repetitive and/or sensory behaviours. Or they might have the same support level for both.
The DSM-5 says that these levels shouldn’t be used to decide whether a child is eligible for services.
Criteria for social communication disorder diagnosis
Social communication disorder (SCD) is similar to autism spectrum disorder. The main difference is that children diagnosed with SCD don’t have restricted, repetitive and/or sensory behaviour.
If children have at least two restricted, repetitive and/or sensory behaviours, it could point to a diagnosis of autism spectrum disorder. If not, it could point to a diagnosis of SCD.
Diagnosis of other co-occurring conditions
Sometimes autism comes with other conditions. These are called co-occurring conditions.
If children have signs or characteristics that meet the criteria for other conditions, they’ll be diagnosed as having two or more conditions – for example, autism spectrum disorder and attention deficit hyperactivity disorder (ADHD) or intellectual disability.