A. In May 2013, a new version of the Diagnostic and Statistical Manual of Mental Disorders (DSM) was published – the DSM-5. The DSM-5 changes the way autism spectrum disorder (ASD) is diagnosed. The changes reflect the current understanding of ASD, based on research.

B. When diagnosing ASD, professionals like paediatricians, psychiatrists and psychologists, use the Diagnostic and Statistical Manual of Mental Disorders (DSM), produced by the American Psychiatric Association. The DSM lists the signs and symptoms of ASD and states how many of these symptoms must be present in order to confirm a diagnosis of ASD. The DSM-5 replaces the old manual (DSM-IV).

C. The DSM-5 makes the following key changes to ASD diagnosis.

1. New single diagnosis of ASD
This single diagnosis replaces the different subdivisions – autistic disorder, Asperger’s disorder and pervasive developmental disorder – not otherwise specified.

2. New severity ranking
An ASD diagnosis now has a severity ranking – level 1, 2 or 3. The ranking depends on how much support the person needs. This reflects the fact that some people have mild symptoms and others have more severe symptoms.

3. ASD diagnosis based on two areas
Professionals will now diagnose ASD on the basis of difficulties in two areas. A child will need to have difficulties in both areas to be diagnosed with ASD. This approach replaces the previous three areas – social interaction, language and communication and repetitive and restricted behaviour and interests.

a. Social and communication problems have been merged into one area – deficits in social communication. Difficulties in this area include rarely using language to communicate with other people, not speaking at all, not responding when spoken to, or not copying other people’s actions, such as clapping.

b. The second area is fixated interests and repetitive behaviour. Examples of this include lining toys up in a particular way over and over again, or having very narrow and intense interests.

4. Sensory sensitivities
Sensory sensitivities were not previously included in the DSM-IV. In the DSM-5, they have been included as behaviour within the fixated interests and repetitive behaviour category. Examples might be, not liking labels on clothes or eating only foods of certain colours or textures.

5. Symptoms from early childhood
According to the DSM-5, in order for a child to be given a diagnosis of ASD, he or she must have shown symptoms from early childhood, even if these are not recognised until later.
This change has been made in order to encourage professionals to diagnose ASD in early childhood. It also means that a diagnosis can be made as soon as it becomes clear that a child’s abilities aren’t equal to the social demands being put on them. For example, at an age when a child is expected to have two-way conversations, you might notice that he can answer only simple questions.

6. Diagnosis of two or more disorders
If a child has other symptoms that meet the criteria for other disorders, she/he will be diagnosed as having two or more disorders – for example, ASD and ADHD. This technically wasn’t possible with the DSM-IV, although many professionals did diagnose other disorders along with ASD.

D. New diagnosis of social communication disorder (SCD)
Social communication disorder (SCD) is similar to ASD. But according to the DSM-5, the main difference between SCD and ASD is repetitive behaviour. It will take time and clinical practice experience for the meaning of this category to become clear. If a child has at least two repetitive behaviours, it could point to a diagnosis of ASD. If not, it could point to a diagnosis of SCD.

E. What the changes will mean for your child
Children who have already been given a diagnosis
If your child already has a diagnosis of autism spectrum disorder (ASD) – autistic disorder, high-functioning autism, Asperger’s syndrome or PDD-NOS – these changes won’t affect him/her. You don’t need to do anything and you can keep using these terms if you want to.

Children waiting for a diagnosis
If your child is diagnosed or reassessed after May 2013, he/she’ll be assessed with the DSM-5 criteria and will be given a diagnosis of autism spectrum disorder (ASD), rather than autistic disorder,

G. Asperger’s syndrome or PDD-NOS.
Some children who would have met the DSM-IV criteria for autism or related conditions might not meet the DSM-5 criteria. Some might be classified under the new category of social communication disorder (SCD).
A few children might miss out on a diagnosis. Recent research indicates that this is likely to be around 5% of children who meet the old criteria.

(American Psychiatric Association (2013). Diagnostic and statistical manual of mental disorders (5th edn) (DSM-5).)