A full evaluation should be done by a multi-disciplinary team of healthcare professionals, which may include a paediatrician specialising in behavioural and developmental paediatrics, a child psychiatrist or psychologist, and a speech or occupational therapist. Doctors may also call for a hearing test to be performed by an audiologist to ensure that hearing loss is not the primary underlying reason for the lack of social communication and interaction. Your doctor may also recommend a blood test, genetic test, or brain scan to rule out the presence of other medical conditions that can co-occur with ASD.
In addition, the doctor may give out questionnaires to parents and teachers to ascertain if the child has difficulties at home or in school that maybe related to ASD.
Children can be screened for the disorder from as young as 18 months, and a diagnostic assessment can be done from 31 months. However, it is sometimes difficult to distinguish between ASD and global developmental delay at a young age, and each child might present differently. Your doctor will thus determine the most suitable age for your child to be assessed.
It is important to identify children with possible ASD early so that they can receive appropriate intervention and support services that are targeted to address their learning needs. Research indicates that early intervention can improve children’s developmental outcomes, including improved language, cognitive, social and motor skills.
A diagnosis is also helpful for school-going children. It allows for schools to allocate resources (e.g. allied educator or special programmes) to support them. Exam accommodations and leniency in marking of some tests may also be applied for should it be deemed necessary by the psychologist and/or school
Testing for ASD
There are several assessment tools that are available for diagnostic purposes, including the most commonly used ASD Diagnostic Observation Schedule (ADOS) and ASD Diagnostic Interview-Revised (ADI-R). These are conducted by psychologists who are trained to use them. Measures of the child’s speech and language skills and intellectual ability also help professionals plan intervention.
- The ADI-R is a standardised, semi-structured clinical interview for caregivers. The interview takes 2 to 3 hours and it focuses on behaviours in three areas: quality of social interaction; communication and language; and repetitive, restricted and stereotyped interests and behaviour.
- The ADOS is a semi-structured, clinic-based play observation. The observation requires 40 minutes to an hour. It involves activities like playing with toys, looking at pictures, and snack time. The activities assess a child’s social communication, social interaction and play or imaginative use of materials.
A typical ASD assessment requires a total of 3 to 4 hours, and is conducted over about three sessions. The assessment sessions will be scheduled based on the availability of the psychologist and parents.
Preparing for the ASD assessment session?
For sessions with the child:
- Allow the child to have plenty of rest the night before.
- Have meals on the day of the test.
- Talk to your child about where he/she will be going, who he/she will meet, and what he/she may do.
- Reach 10 to 15 minutes before the time of test to let your child get used to the clinic environment.
- Please reschedule the session if your child is unwell or feeling tired.
For parent interviews:
- Take leave or ensure you will not be interrupted during the time of the interview.
- Review your child’s past medical records or videos to note his/her speech and motor developmental milestones. It will be very helpful to recall and/or observe your child’s interactions with familiar and unfamiliar adults and children. Do note any unusual behaviours and interests (e.g. spinning body, lining up objects etc.) and how long these behaviours have lasted.
- If your child is above 5 years old, recall his/ her behaviours at the particular period when he/she was 4 to 5 years’ old.