Autism Spectrum Disorder

What are the signs and symptoms of autism?


With the advancement in diagnostic tools, most children with autism can be reliably diagnosed by the age of 3, and earlier diagnosis is even possible for children as young as 12 months old.

Parents are usually the first to notice peculiarities with their child’s development that do not follow the typical norm. Some of these peculiarities noted by parents include sudden regression and onset of social aloofness and/or a lack of progress after the child has reached certain developmental milestones.

Although symptoms of autism vary from child to child, the core areas affected include:

  • Deficits in language and communication
  • Impairments in socialization and social interactions
  • Undeveloped cognitive and adaptive functioning
  • Restricted repetitive and stereotyped patterns of behavior and interests

These essential skill deficits cause children to fall progressively further behind their typical peers as they grow older. The cause is unknown, but evidence points to physiological and neurological abnormalities. Children with autism generally do not learn in the same way that children normally learn, because, in part, they lack the fundamental skills which enable them to acquire and process basic information. These difficulties result in significant delays in their development of language, play and social skills, including their failure to notice and learn through imitation of their peers.

  • As of December 2021, about 1 in 44 children has been identified with autism spectrum disorder (ASD) according to estimates from CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network, which is 50 percent higher than previous estimates reported in 2012 of 1 in 88 children
    (Center for Diseases Prevention and Control, CDC 2014)
  • 1,100,000 cases of autism in China; 650,000 in the UK; 500,000 in the Philippines; and 180,000 in Thailand
    (the World Health Organization, WHO, 2009)
  • 49 children in every 10,000 is diagnosed with the disorder in Hong Kong
    (epidemiological study by V. Wong & S. Hui (2007) of The University of Hong Kong)
  • ASD is more than 4 times more common among boys than among girls.
    (Centers for Disease Control and Prevention, CDC, ASD)  Read article
  • Studies in Asia, Europe, and North mAmerica have identified individuals with ASD with an average prevalence of about 1%. A study in South Korea reported a prevalence of 2.6%.
    (Centers for Disease Control and Prevention, CDC, ASD)
  • Approximately 67 million people worldwide are affected by autism.
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