Autism Spectrum Disorder

Autism Spectrum Disorder Autism Spectrum Disorder

What is autism spectrum disorder?

Autism spectrum disorder (ASD) is a neurodevelopmental disorder, characterised by different degrees of impairment and deviance in the development of social communication, cognition and emotions, and presence of restricted, repetitive patterns of behaviours and interests as well as sensory processing problems. Other areas of impairments, such as intelligence and language, may co-exist.

About different names of ASD

With new diagnostic criteria in recent years, previously used names such as autistic disorder, Asperger’s disorder, high functioning autism, autistic features, atypical autism and pervasive developmental disorder not otherwise specified are subsumed under the new diagnosis of "autism spectrum disorder" (ASD) to reduce confusion.

Impacts on children's growth

ASD creates various challenges which change along with the child’s different developmental stages. The syndrome can cause significant impact on parent- child relationships, peer relationships and adjustment to school and society. Children with ASD vary greatly in the overall functioning depending on the individual’s age, language and intellectual development, as well as other factors such as treatment history and ongoing support.


How common is autism spectrum disorder?

How common is autism spectrum disorder?

Prevalence rate

According to a local study published earlier, about 0.16% of Hong Kong children below 15 has an ASD diagnosis.
Besides, according to the General Household Survey conducted during 2019 and 2020 by the Census and Statistics Department, prevalence rate among local population below 15 with ASD is estimated at around 1.4%.

(*There may be variations in the estimated prevalence rates due to differences in the definition of disorder, age of subjects, and year and ways of data collection among studies and surveys.)

Gender ratio

ASD affects more boys than girls and the ratio is 6.58 to 1.


What causes autism spectrum disorder?
Mostly genetics

Though the exact cause is still not fully delineated, ASD is now widely accepted to be a neurodevelopmental disorder that is highly heritable and resulting from multiple genetic and non-genetic causes.

Heritability is demonstrated by the higher recurrence rate of siblings of children with ASD. About 10% of children with autism are also identified as suffering from Down’s syndrome, fragile X syndrome, tuberous sclerosis or other genetic and chromosomal disorder.

*Know more – Myths of ASD

  • Is ASD caused by poor parenting?

    No. Empirical findings have refuted poor parenting as a cause.

  • Will measles, mumps, and rubella vaccine trigger ASD?

    No. There is overwhelmingly strong evidence that the measles, mumps, and rubella vaccine is not associated with ASD.


What are the symptoms of autism spectrum disorder?

What are the symptoms of autism spectrum disorder?

Owing to individual differences and their complex interplay under different social contexts, the behavioural manifestations of the core features of children with ASD can vary greatly. The followings are some common clinical presentations:

Deficits in social interaction
  • Social interaction difficulties may vary from being aloof, passive to over-passionate, or odd mannered behaviours.
  • Some of the very young children with ASD may only approach adults for addressing physical or biological needs, such as getting food or toys. For these, they may use others as mechanical aids to get what they need. Some may show aversion to physical contact and stiffen when held.
  • They may show limited social relatedness and attachment with parents or close care-takers, and prefer to play alone and with little or no spontaneous sharing of interest, enjoyment and achievements; some may show motivation to socialize but act over- passionately or self-centered.
  • Older children may still fail to initiate appropriate social signaling to others (e.g. socially directed smiles, eye to eye gaze), and lack response to others’ signals in social situations.
  • For those who have developed useful verbal language, communication is still often used for instrumental rather than social purposes. Apart from aloofness, some may have social attempts when instructed by adults but with low social volition, while others with higher social intention may appear odd, over-passionate and self-centered.
Deficits in non-verbal communication
  • Children with ASD are weak in the use of non-verbal communication. Very young children with ASD may have difficulty indicating needs through pointing and eye- gazing.
  • Limited facial expression and poor eye contact may render them to be seemingly rude, uninterested or inattentive in social interactions.
  • Some may speak with high-pitched voices, strange prosody or with robot-like monotone.
  • Older children may have difficulty in understanding social cues from body language and tone of voice. The overall integration of verbal and non-verbal communication is weak.
Deficits in relationship and friendship building
  • Children with ASD lack adequate social skills to develop friendships with others.
  • Many children with ASD have speech and language difficulties, such as weak fund of vocabularies, pronominal reversals, which affect their ability to converse effectively with peers and in friendship building.
  • Even for those with intact language and who are eager to make friends, the weakness in empathy to understand others’ thoughts and feelings creates a range of challenges. These include difficulties in processing complex social cues and understanding implicit social rules, regulating behaviour to match specific social context, following rules of the communication context, and understanding non-literal languages including jokes, idioms and metaphors.
  • Friendships are often one-sided or based solely on shared special interests. Inappropriate attempts at social interchange are often interpreted as aggressive or disruptive behaviour as they may be socially immature, mechanical, awkward or overly passionate.
Stereotyped or repetitive motor movement or use of objects/ speech
  • Restricted and ritualised patterns of verbal or nonverbal behaviours (such as lining of objects and repetitive opening and closing doors) are common during early and middle childhood.
  • Stereotyped body movements (stereotypies) such as flapping of hands, running back and forth, head banging, rocking of body, self-spinning, and finger movements may be present when these children become excited, distressed or agitated.
  • Some children may keep repeatedly watching the same movie or reading the same story book.
  • The unusual speech pattern may include stereotyped words or phrases which are out of the social context, immediate or delayed echolalia (inappropriately repeating other people’s spoken words), repetitive questioning, and greeting rituals, and for some older children pedantic speech with vocabularies or phrase that are unusual for age or social group may be seen.
Insistence on sameness
  • Children with ASD often show insistence on sameness or excessive adherence to routines. Insistence on taking the same route, maintaining same arrangement for objects, eating a narrow range of food items, adopting rigid thinking patterns are some common examples.
  • Many respond to small changes in the environment with disproportionate distress, including change in routine, transition from one activity to another, and moving to new home or classes with changes of people and environment.
Fixated interest
  • Fixated or narrow interests are very common in children with ASD. Some demonstrate strong memory of information and data and fascination with numbers, bus routes, calendar and natural sciences.
  • In early infancy and early childhood, commonly there is absent or minimal exploratory play or symbolic/fantasy play (for example playing teacher/doctor games). Instead, the play is monotonous and repetitive, and lacking variation, such as spinning and lining activities.
  • For older children, including those with high functioning, there may be limited imitation, creativity and imagination. They may have unusual preoccupation with parts of objects, or perseverative interests with particular topics, all leading to negative impact on their daily and social functioning.
Sensory issues
  • Some children with ASD have sensory processing problems of hyper- or hypo-reactivity to sensory input or unusual interest in sensory aspects of the environment. Some show apparent indifference to pain, heat or cold, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement (e.g. spinning objects). They may present sensory seeking or avoidance behaviours to usual sensory stimulation.



How to treat children with autism spectrum disorder?
Behavioural and educational training

There is no medical cure for ASD. The current mainstay of intervention for ASD is to improve the overall functional status of the child through behavioural and educational training, social adjustment, as well as continual parental support.

Key points in treating autism spectrum disorder:

  • To address the individual needs of each child: training strategies should be tailor-made based on professional assessment in such areas as social communication, language, play skills, and adaptive behaviours.
  • Early, intensive and sustained interventions: the use of multiple treatment modalities carried out in natural settings, and active parental involvement, are proven to be more effective.
  • Parental participation: to provide support to the parents during treatment to facilitate implementations of the learned skills in daily living and community settings.

Medication has not been shown to be able to cure core social or communication impairments of ASD. However, using medication to reduce some specific behaviours such as aggression, self-injurious behaviour, anxiety, stereotypes, compulsive behaviour, mood disturbances, hyperactivity, inattention, and sleep problems can enhance the child’s ability to benefit from other educational and behavioural modification interventions.

It has been known that early tailor-made intensive behavioural and educational interventions can significantly improve the clinical outcome. Therefore, it is essential to seek help from your doctor timely if indicated. Parents' participation is also crucial.

For more details, please visit:



How to support and help children with autism spectrum disorder?

Rehabilitation service & educational placement:

Children diagnosed with ASD by professionals will be referred to suitable training and education support services based on their ability. The training each child requires varies, but generally includes training in cognition, language and physical coordination.

Preschool School-aged
Target preschool children (aged 2 to 5) with mild developmental delay Choice of special schools or mainstream schools mostly depends on their cognitive ability
  • Early Education and Training Centre (EETC)
  • Integrated Programme in Kindergarten-cum-Child Care Centre (ICCC)
  • Special Child Care Centre (SCCC) – for those who need more intensive support
  • Special schools: there will be additional resource teachers to implement specific programs on behavioural management, as well as training of communication and social skills.
  • Mainstream schools: additional support through special teaching and behavioural management should be provided.
Family support:
Voluntary organisations Non-government agencies and various parent associations organise regular activities, workshops and talks catering for the needs of children and families with ASD.
Parent associations Parent associations and support groups and parent resource centres also play important supportive roles.
Public education Public education helps to enhance public awareness and understanding of the various challenges to children with ASD and their families in different developmental stages.


Can children with autism spectrum disorder grow up normally?

The outlook of a child's subsequent development depends largely on the severity of ASD and the child's cognitive and language abilities. Unfavourable factors include:

  1. presence of intellectual disability,
  2. seizures, and
  3. absence of functional speech by the age of 5-6 years.

Adolescents and adults with ASD are confronted with challenges in social, academic, vocational and daily functioning. With early intervention, better understanding and acceptance from family and community, individuals with ASD can enjoy positive and rewarding lives.




"香港社會服務聯會- 社聯頻道" 高能力自閉症人士:「請講野直接d,唔好兜圈」 "香港社會服務聯會- 社聯頻道" 「創意藝術」助SEN學生 Radio i Care 友心情網上電台YouTube channel中有關自閉症的短片
香港社會服務聯會- 社聯頻道 香港社會服務聯會-社聯頻道「創意藝術」助sen學生 Radio i Care 友心情網上電台YouTube channel中有關自閉症的短片

Reference source(s): Website of Child Assessment Service, Department of Health