About the DSM and autism spectrum disorder diagnosis
When diagnosing autism spectrum disorder (ASD), 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 ASD and states how many of these symptoms must be present to confirm a diagnosis of ASD.
To find out whether a child has these symptoms 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.
In the DSM-5 there are some key changes to autism spectrum disorder (ASD) diagnosis. There’s now a single diagnosis of autism spectrum disorder that replaces the different subdivisions – autistic disorder, Asperger’s disorder and pervasive developmental disorder – not otherwise specified (PDD-NOS).
There’s also a separate diagnosis of social communication disorder.
DSM-5 criteria for ASD diagnosis
Professionals diagnose autism spectrum disorder (ASD) on the basis of difficulties in two areas – social communication, and restricted, repetitive behaviour or interests.
To be diagnosed with ASD, children must:
- have difficulties in both areas
- have had symptoms from early childhood, even if these aren’t picked up until later in childhood.
Difficulties in social communication
Children must have difficulties in the area of social communication to be diagnosed with ASD.
Signs of difficulties in this area include:
- rarely using language to communicate with other people
- not speaking at all
- not responding when spoken to
- not sharing interests or achievements with parents
- not using or understanding gestures like pointing or waving
- not using facial expressions to communicate
- not showing an interest in friends
- not engaging in imaginative play.
Restricted, repetitive behaviour or interests
Children must have difficulties in the area of behaviour and interests to be diagnosed with ASD.
Signs of difficulties in this area include:
- lining toys up in a particular way over and over again
- speaking in a repetitive way (echolalia)
- having very narrow and intense interests
- needing things to always happen in the same way
- having trouble with changing from one activity to another
- showing signs of sensory sensitivities like not liking labels on clothes, or licking or sniffing objects.
An ASD diagnosis includes a severity ranking, which 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 rankings reflect the fact that some people have mild ASD symptoms, and others have more severe symptoms.
The rating is given separately for the two areas of difficulty, so children might have different severity rankings for social difficulties and repetitive behaviours.
Criteria for social communication disorder diagnosis
Social communication disorder (SCD) is similar to ASD. The main difference between SCD and ASD is repetitive behaviour.
If children have at least two repetitive behaviours, it could point to a diagnosis of ASD. If not, it could point to a diagnosis of SCD.
Diagnosis of other disorders
If children have symptoms that meet the criteria for other disorders, they’ll be diagnosed as having two or more disorders – for example, autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD).
Children who were diagnosed before DSM-5
If your child already has a diagnosis of autism spectrum disorder (ASD) – autistic disorder, high-functioning autism, Asperger’s syndrome or PDD-NOS – that was made under DSM-IV, you can keep using these terms if you want to.
In some circumstances, you might need to get a letter confirming your child’s diagnosis under DSM-5. For example, some schools want a new diagnosis letter confirming a DSM-5 diagnosis to ensure funding for your child.
The DSM-5 states that anyone with ‘a well established DSM-IV diagnosis of autistic disorder, Asperger’s disorder, or pervasive developmental disorder not otherwise specified should be given the diagnosis of autism spectrum disorder’. Your child’s health professional will just need to add a severity rating.