top of page

Autism (Autism Spectrum Disorders)

Frequently Asked Questions

What is autism spectrum disorder (ASD)?

ASD is a complex neurodevelopmental condition that affects people worldwide. It is characterized by difficulties in social communication and the presence of repetitive behaviors or interests.

How common is ASD?

When examining different regions, the prevalence of ASD varies. In North America, the prevalence is higher at 1.01%. In Europe, it is 0.73%, and in Asia it is 0.41%. Among specific countries, the United States has the highest prevalence at 1.12%, while Taiwan has the lowest at 0.11%. (Source: Talantseva OI et al. Front Psychiatry. 2023 Feb 9;14:1071181)

The most recent report by the CDC's Autism and Developmental Disabilities Monitoring Network reveals a significant increase in ASD prevalence. Since the first study in 2000, there has been a 243% increase. - Maenner MJ et. Al. MMWR Surveill Summ. 2021 Dec 3;70(11):1-16.


What are the clinical features of ASD?

Early signs of ASD can be observed in the first two years of life of a child. These include:

  • Not responding to their name

  • Limited use of gestures for communication, and

  • Lack of imaginative play.


When to suspect ASD?

While each child is unique, here are some indicators that may warrant a closer look and consideration of ASD are:

  1. Trouble with Socializing: The child might find it hard to interact with others, like making eye contact, understanding social cues, and sharing their feelings or experiences.

  2. Communication Differences: The child may have difficulty with language skills, such as talking later than expected, using repetitive words or phrases, having a limited vocabulary, or relying more on gestures than words.

  3. Repetitive Actions and Interests: The child might repeat certain behaviors like hand-flapping, rocking, or arranging objects in a specific way. They may also be very interested in certain topics or objects and focus on them a lot.

  4. Sensitivity to Senses: Children with ASD might be more sensitive to things like loud noises, bright lights, or certain textures. On the other hand, they may seek out sensory input, like spinning or touching objects excessively.

  5. Unusual Play: Their way of playing might be different from other kids. They may engage in repetitive or solitary play, show less imagination, or be really focused on specific objects or parts of toys.

  6. Trouble with Changes: Children with ASD may find it hard to handle changes in routines, transitions, or unexpected events. They might get upset or prefer things to stay the same.


What is the cause of ASD?

The exact cause is not fully understood. It is believed to be a complex condition caused by a combination of genetic and environmental factors. Here are some key points about the potential causes of ASD:

  1. Genetic Factors: Research suggests that certain genes may play a role in the development of ASD. Studies have shown that there is a higher risk of ASD in families with a history of the disorder. However, no single gene has been identified as the sole cause of ASD.

  2. Environmental Factors: Some environmental factors, such as prenatal and early-life exposures, may contribute to the development of ASD. These factors can include maternal infections during pregnancy, exposure to certain medications or chemicals, and complications during birth.

  3. Brain Development: Studies have indicated that ASD may be associated with abnormal brain development. Differences in the structure and functioning of the brain, particularly in areas related to communication, social interaction, and sensory processing, have been observed in individuals with ASD.

  4. Neural Connectivity: It is thought that disruptions in the connections between different areas of the brain, known as neural connectivity, may be involved in the development of ASD. These disruptions can affect how information is processed and integrated, leading to the characteristic symptoms of ASD.

It is important to note that ASD is not caused by factors such as parenting style, vaccines, or psychological trauma, as these have been thoroughly studied and disproven as causes of the disorder.


How is ASD diagnosed?

  • Diagnosing ASD requires a comprehensive evaluation by a multidisciplinary team using standardized measures such as the Autism Diagnostic Observation Schedule and the Autism Diagnostic Interview.

  • Individuals with ASD often experience higher rates of depression, anxiety, sleep difficulties, and epilepsy compared to those without ASD. Sometimes Blood investigations, EEG, MRI may be required to rule out co-existing causes.


How is ASD treated?

  • Intensive behavioral interventions, such as the Early Start Denver Model, can be beneficial for children aged five and younger, leading to improvements in language, play, and social communication.

  • Pharmacotherapy may be prescribed for co-occurring psychiatric conditions, with medications such as risperidone and aripiprazole shown to improve irritability and aggression.

  • Psychostimulants are effective for attention-deficit/hyperactivity disorder.


What is the prognosis of ASD?

The prognosis for individuals with autism can vary, but early intervention, appropriate support, and understanding can greatly improve outcomes and enhance their quality of life.

Continued research, access to resources, and a society that embraces neurodiversity are crucial for supporting individuals with autism and ensuring they have the opportunities to thrive.


Dr. Lekhjung Thapa, MD, DM (Neurology)
Associate Professor of Neurology
Senior Consultant Neurologist

Dr. Lekhjung Thapa, MD, DM (Neurology)
Associate Professor of Neurology
Senior Consultant Neurologist
bottom of page