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Doctor and Patient


Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a congenital developmental disorder that affects child’s social development and behavior. Some of the affected children may also have developmental delay, intellectual impairment, language delay, emotional or other behavioral problems. The diagnostic criteria (DSM-V) had been revised in 2013, and the terms including Autism, Asperger's disorder, pervasive developmental disorder (PDD), high functioning autism and atypical autism are no longer use and all the above conditions are classified under the category of Autism Spectrum Disorder.

Is Autism Spectrum Disorder a common condition?

According to the data from Centers for Disease Control and Prevention (CDC) in 2016, the prevalence of autism spectrum disorder was about 1 in 54 children. It was 4 times more common in boys than in girls. Around 17% of them was also diagnosed with other developmental disabilities.

What causes Autism Spectrum Disorder?

The exact causes of Autism Spectrum Disorder are still not known, but it is generally accepting that the cause is multifactorial, while genetic predisposition play a role. Many of the researchers found that the affected individuals might have genetic mutations, imbalance of neurotransmitters in brain, variation of brain structures or inborn error of metabolism. Some of them may be affected by maternal intake of drugs during pregnancy. The previous suspected linkage of MMR vaccine to Autism Spectrum Disorder was refuted by subsequent multiple extensive studies.

What are the symptoms of Autism Spectrum Disorder?

The diagnosis of Autism Spectrum Disorder is made clinically. The assessment also involves assessing other concurrent developmental disabilities, and exclusion of other developmental conditions that might have similar presentation. Presentations of affected child could be quite different. According to the diagnostic criteria (DSM-V), they are weak in social communication and have different behavioural problems.

Social communication difficulties:
  1. Deficit in social interactions:
    • Aloof, passive

    • Over-passionate

    • Prefer to play alone

    • Use other person’s body part as tools

    • Weak eye contact

    • Weak in sharing (emotion, interest)

    • Shows aversion to physical contact, or inappropriate physical contact

    • Difficult to start or sustain conversation

  2. Weak in non-verbal communication:
    • Weak eye contact

    • Weak in using gesture to communicate/express needs

    • Lack of facial expression

    • Lack of pointing to indicate needs

    • Monotonous speech

  3. Deficits in developing, maintaining, and understanding relationships:
    • Difficulties adjusting behaviour to suit various social contexts

    • Difficulties in sharing imaginative play

    • Difficulties in making friends

    • Absence of interest in peers

Behavioural problems:

  1. Stereotyped or repetitive motor movements, use of objects, or speech
    • Repetitive body movement (e.g. self-spinning, body rocking, arm flapping)

    • Lining up toys or flipping objects

    • Echolalia

  2. Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior
    • Extreme distress at small changes , insist to follow same agenda

    • Insist same way to play

    • Need to take same route or eat same food every day

    • Difficult to adapt new environment or accept new food

  3. Highly restricted, fixated interests that are abnormal in intensity or focus
    • Fixated and narrow interest with strong memory (letters, numbers, bus route, train stations, calendar, animals)

    • Preoccupation with part of an object (e.g. car wheels)

  4. Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment
    • Adverse response to specific sounds or textures

    • Excessive smelling or touching of objects

    • Visual fascination with lights or movement

How does Autism Spectrum Disorder affect my children?

Autism spectrum disorder affects child’s social communication and behaviour. Symptoms could become noticeable from the age of 1 to 2 years old. Parents may find their child have speech delay, or weak in social interactions. Some affected children may exhibit behavioural problems such as repetitive behaviour or restricted interest. Delay in speech development may further affects child’s learning and social skills. Some children with mild autism spectrum disorder might not have noticeable symptoms in toddler years. Their symptoms may be more obvious when social demands become more prominent in school age. They might become more rigid and may develop fixated and restricted interest. They might appear to be weak in understanding the hidden rules in different social context. These may be presented as difficulties in making friends and maintaining relationships with others. These difficulties will persistently affect them into adulthood, which give them more challenges at work and handling relationship with others. Continuous training especially on social skills can positively improve their functioning.

How to diagnose Autism Spectrum Disorder, and what are the treatment?

The current mainstay of treatment is behavioural and education training, social skill training and support. Medication is only for individual cases with severe emotional problems or aggressive behaviours. The aim of the training is to improves child’s social motivation and interaction skills and manage their behavioural problems by education and behavioural modifications. Some children may also be beneficial from sensory integration training. Different training strategy has different approaches. Early intervention and intensive training usually have better results. Consistent approach by parents and teachers are also important to avoid confusion by child.

Common training strategy:

  1. Behavioural approach:

    Applied Behaviour Analysis (ABA) is the practice of applying the psychological principles of learning theory in a systematic way to modify behaviour. The instruction plan breaks down each of these skills into small, concrete steps. The therapist teaches each step one by one.

    Picture Exchange Communication System (PECS) allows people with little or no communication abilities to communicate using pictures.

  2. Relationship-based approach:

    Developmental, Individual Differences, Relationship-based approach (Floor time) is a relationship-based therapy for children with autism spectrum disorder. Based on child’s current developmental capacity, therapists and parents follow child’s lead, and engage child through the activities he/she enjoys. The training enhances child’s social communication, self-regulation, motor, sensory and cognitive development.

  3. Social cognitive approaches:

    Social stories enable child to understand the social norms and behavioural expectation in different social context.

    Theory of Mind is the training for child to interpret and understand other’s beliefs, desires, plans, hopes, information, and intentions, that may differ from our own.

  4. Structured teaching approach:

    Treatment and Education of Autistic and related Communication handicapped Children (TEACCH) focuses on the unique learning needs of children with ASD, including strengths in visual information processing, difficulties with social communication, attention and executive function. The approach utilizes visual and/or written information to supplement verbal communication, individual schedules, structured environmental organization and activity systems to facilitate their learning and social communication.

    There is no single approach that fits all children, parents are encouraged to discuss with their doctor for suitable training strategy.

If I worried my child has autism spectrum disorder, what shall I do?

If you worry you child has symptoms of autism spectrum disorder, early comprehensive assessment by paediatrician or psychologist is recommended. Parents can seek private assessment by paediatrician / psychologist or refer by registered doctor to Child Assessment Centre. After comprehensive assessment on child’s ability, paediatrician or psychologist will formulate recommendations of training plan for your child.

Preschool rehabilitation service under Social Welfare Department provides comprehensive service to preschool child (under 6 years of age), which includes speech therapy, occupational therapy, physiotherapy. Children meet the criteria must be referred by paediatrician or psychologist to apply. Parents can choose to receive service from Early Educational Training Centre (EETC), Integrated Programme in Kindergarten-cum-Child Care Centre (ICCC), On-site Pre-school Rehabilitation Services(OPRS) or Special Child Care Centre( SCCC) according to child’s condition.

Education Bureau (EDB) provides support to school age child with special education needs (SEN) in mainstream primary and secondary school. EDB provides training to teachers, set up guidelines for school to formulate individual learning plan to cater the needs of students with SEN. Children who need extra supports and cannot cope with mainstream curriculum will be supported by special schools.

Early assessment and intervention are crucial to child’s development and outcome. Parents should seek professional advice as early as possible when suspect child has developmental problems.


According to the figures given by the Education Bureau, children diagnosed to be suffering from ASD rose from 3801 in 2014/2015 to 5693 in 2018/2019. The increase has been almost 50%. From previous study, it is estimated that 1 in every 100 children will be suffering from ASD (around 1%). Boy to girl ratio was roughly 4-5 : 1.

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