Autism Spectrum Disorder — Definition, Symptoms, Treatments and Facts

Autism Spectrum Disorder — Definition, Symptoms, Treatments and Facts

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder, characterised by the differences found in the development of the brain. It was Leo Kanner, who in 1943 went on to publish the first organised description of infantile autism.

Kanner claimed infantile autism to be innate, a courageous hypothesis against the then-dominant view of Freudian Psychology and the ideas of “poor parenting” and “frigid mothers” to be some of the causes of this disorder.

Since 1943, science has taken numerous leaps and notable progress has been made to understand the causes of ASD. The Diagnostic and Statistical Manual of Mental Health (DSM-5 TR) defines ASD as persistent deficits in social communication and restricted, repetitive patterns of behaviour.

Research evidence suggests that the disorder exists on the spectrum, that is, it consists of a diverse range of conditions. With the progress made in understanding the causes of ASD, there are also intervention strategies that have been designed to help optimise and quality of life, development as well as well-being of people with autism.

What is Autism and How to Define it?

As mentioned before, the DSM defines autism as a disorder that exists on a spectrum. This is because ASD consists of a wide range of symptoms, behaviour and levels of impairment. Every autistic person's experiences vary considerably in the symptoms and challenges they face.

By defining Autism as a spectrum, we recognise the diversity that exists concerning this disorder and how it affects people in various ways. For example, some autistic people might be nonverbal, on the other hand, some can speak their spoken language pretty proficiently.

Typically autism spectrum disorder is characterised by deficits in social communication and repetitive patterns of behaviour. The disorder also leads to an inability to function in social, academic as well as occupational settings.

Psychiatry has classified ASD as a mental disorder. Researchers as well as members of the autism rights movement argue otherwise. They have stated that autism, especially high-functioning autism, should be considered as the natural part of human neurodiversity.

Therefore the perspective has focused on how accommodating autistic people is necessary rather than trying to fix or change them. Moreover, they state that it is the societal structures and not the inherent personal flaws that create obstacles for autistic people.

The research on autism spectrum disorder has taken leaps and efforts are continuously being made to understand the complexity of this disorder.

Prevalence of Autism

Autism Spectrum Disorder (ASD) occurs amongst people of all socio-economic, racial and ethnic groups. Research conducted by the Centre for Disease Control and Prevention reports that ASD is 4 times more likely to occur in boys than in girls.

The Centre for Disease Control and Prevention has an Autism and Developmental Disabilities Monitoring (ADDM) Network. According to ADDM, 1 in 36 children have been found to have ASD. In 2019, the World Health Organization revealed that 1 in 100 children are diagnosed with ASD worldwide.

The estimated prevalence of Autism in India as reported by a study that was featured in the Indian Journal of Pediatrics is 1 in 68 children.

Types of Autism

Historically five types of Autism were categorised. However, today this classification is considered out of date. The diagnostic and statistical manual of mental disorders stages shows that ASD exists on a continuum with different signs and symptoms.

Although the older terminology has been removed and people now received the diagnosis of Autism Spectrum Disorder, the previous terminology hasn't been eliminated from conversations.

Historically, the five identified types of Autism are as follows:

Kanner’s Syndrome: This is also known as “classic autism.” This is what people “think” of when they hear the term autism. It is named after Leo Kanner, who in this classic 1943 study identified 11 children with distinct social and behavioural patterns.

Kanner noted now the children engaged in repetitive patterns of behaviour like flapping their hands and also had disinterest in their environment. He also noticed their struggle with change and the difficulty they experienced with speech such as echolalia (constant repetition of words).

Rett Syndrome: Rett Syndrome is a genetic condition mostly occurring in girls. Affected individuals show symptoms like repetitive hand movements as well as difficulties with their motor skills. They also have various cognitive and physical impairments such as disease in head growth and loss of speech milestones.

Asperger's Syndrome: Asperger's Syndrome is now viewed as a milder form of autism. Hans Asperger identified that despite having typical language development, certain individuals could be categorised based on shared differences in their social interactions with others. These individuals also exhibited a deep interest in certain topics.

Today, Asperger's Syndrome no longer remains a diagnosis in the DSM-5 TR, as clinicians and researchers believe that the symptoms of autism and Asperger's syndrome became difficult to distinguish for psychologists and which diagnosis would be provided started to depend on who was performing the assessment.

Childhood Disintegrative Disorder: This was also known as “Heller's Syndrome.” Children with this Disorder have a normal development until the age of three or four. After this, they seem to lose some of their acquired skills and developmental milestones such as language and speech skills.

Pervasive Developmental Disorder - Not Otherwise Specified (PDD - NOS): When individuals exhibit symptoms but don't meet the criteria for other types of autism, this diagnosis is given. This is also known as “atypical autism.”

The Three Functional Levels of Autism

The three levels of autism describe how much support a person with autism needs. These levels are like labels that show how much support someone might need. However, they don't always match how someone acts every day. Some people might show traits from different levels at different times, or they might change between levels from day to day.

Level 1: This is also known as high-functioning autism as level 1 indicates people who don't need a lot of support. A person with level 1 ASD might show difficulty in social communication such as communicating using full sentences or engaging in back-and-forth conversation. They might also experience burnout from masking or camouflaging their symptoms.

Autistic people are often made to believe that to fit in, they need to suppress their neurodivergent traits and present neurotypical patterns of behaviour. Therefore, masking, that is, suppressing their pattern of thoughts and behaviour, can be considered a social survival strategy. This also leads to difficulties in diagnosis.

They might find it hard to switch between activities or try new things. Also, they could struggle with organising and planning. Their independence might not match what's expected for someone their age who doesn't have autism.

Level 2: People diagnosed with ASD level 2 find it difficult to mask their neurodivergent patterns of behaviour. They are also unable to communicate in ways that make them easily understandable to others. They might also find it extremely difficult to move on from one activity to the next.

People with ASD level 2 exhibit repetitive behaviours and have very specific interests. They might also engage in stimming, such as packing back and forth and repeating what they have said. Stimming helps them to feel calm and better.

Everyone stims in some way or the other, such as tapping fingers or humming but autistic people stim more. This is primarily because the societal structures do not cater to the needs of autistic people and they have to bear the responsibility of their own emotions and reactions.

Level 2 autism is more intense and challenging in terms of managing social interaction and completing everyday tasks compared to Level 1.

Level 3: This can also be considered as low-functioning autism. Autistic people at this level show a very high risk for neglect, abuse and discrimination. People in this category have similar traits to those with level 1 and 2 autism, but they are unable to mask and hide their difficulties. They have to work hard to control their emotions and reactions all the time and often fail in doing so.

The difficulties in social communication lead to level 3 autistic people rarely initiating conversations on their own, especially with neurotypical people. This is also because they are likely to be perceived as awkward.

They find it difficult to engage verbally as well as non-verbally. Completing daily tasks also becomes extremely challenging for them.

Assigning people to one of the three levels of autism can help decide what kind of services and support they might need. However, it doesn't capture all the unique things about someone's personality and behaviour. This means the help they get has to be tailored specifically to them.

What are the Causes and Risk Factors of Autism?

The causes of autism are varied. No one factor contributes to ASD. Autism Spectrum Disorder is complex, varying not only in severity but also in its symptoms. Various factors—genetics and environmental factors, contribute to this disorder.

Twin and sibling studies reveal that autism may have a strong heritable component. While researchers are sure that autism has a genetic component, progress is still being made to understand which specific genes are involved with this disorder.

Studies show that different genes are involved with autism and therefore people can develop this disorder in different ways. Some of these are also related to other conditions like ADHD, schizophrenia, bipolar disorder and depression.

While much of the risk for autism is inherited from one’s parents, de novo also contributes to a significant portion of the risk. De novo refers to a genetic mutation that occurs in the egg or sperm but is not present in the parents' DNA.

Certain environmental factors have also been linked to autism. These are:

  • Parental age
  • Teratogens such as air pollutants and pesticides
  • Maternal ailments such as diabetes and obesity
  • Premature birth and birth complications

Symptoms of Autism

Autistic people vary in terms of their symptoms and impairments. One of the key signs of autism is seen during the early years of age when a child seems to avoid eye contact with others, stays apart and aloof from others and doesn't smile or react to social cues.

Autism is usually identified before a child is 30 months of age. Children with autism show a steady decline in their focus on the face and eyes of others as compared to other children. While the focus on people decreases, these children show an increase in focus on inanimate objects instead.

Social Deficit

Children with autism do not seek affection or contact with others. This is due to their lack of understanding of social cues rather than the absence of experiencing emotions. Autistic people also show a deficit in maintaining and understanding social relationships.

Brain Imaging techniques show differences in how social information is processed in autistic people compared to other neurotypical people. Autistic children also struggle with attention as well as locating and orienting sounds in their envoi. They can also be hypersensitive to sensory stimuli. They might struggle with sounds present in their environment, being averse to some sounds and ignoring others.

An Absence of Speech

Autistic children use their speech differently than neurotypical children. They might have little to no speech, often remaining nonverbal or repeating their words again and again. The repetition of words is known as Echolalia.

While young children who are still experimenting with language seem to repeat words that their caregivers have spoken, echolalia is more persistent and pronounced in children with autism. This hinders their communication.


One of the common characteristics and traits found in autistic people is self-stimulation. Autistic children might engage in repetitive movements such as spinning, head banging, and rocking back and forth and this might continue for hours.

Aversion to Change

Autistic children are not easily able to adapt to change. They might form an unusual attachment with things like rocks, pebbles, keys or light switches. When this preoccupation is disturbed such as taking away the things they are attached to, it might lead to crying and intense tantrums until the former situation is restored. They show highly fixated interest and their level of focus seems uncommon in other neurotypical people.

It is said that autistic children are obsessed with the maintenance of sameness.

Other common signs and symptoms that are present in autistic children are:

  • Does not respond to their name by 9 months of age
  • Uses little to no gestures.
  • Does not engage in interactive games like peek-a-boo.
  • Has a fixed way to play with toys.
  • Minor changes upsets them.
  • Delayed language skills.
  • Delayed motor skills.

Treatments of Autism

There isn't one single treatment for autism spectrum disorder (ASD). But getting help, no matter when someone is diagnosed, can make a big difference. People with ASD, no matter their age or ability, can often get better with the right support.

There are many ways to lessen the symptoms and make the most of their abilities. Each person might need different kinds of therapy and help. However, most people with ASD do well with structured and specialized programs. Sometimes, these treatments can help reduce symptoms and make everyday tasks easier.

Seeking timely assistance through various evidence-based psychological intervention programmes can help improve social communication. It’s crucial that after an individual is diagnosed with autism, they, as well as, their caregivers/loved ones, get the appropriate help, care, and support that will cater for their unique needs as they grow and change. Some of them are listed below.

The Picture Exchange Communication System (PECS) is useful for children who experience difficulty with verbal expressive language. The program teaches children to make use of cards with pictures to communicate their needs. For example, approaching a person and giving them a card with a picture of the desired item, to obtain that said item.

The Early Start Denver Model (ESDM) is a behavioural therapy program for children between the ages of 12 months to 48 months. This early intervention aims to support children in developing skills from an early stage so that the differences between the child and their peers can be reduced significantly.

The caregivers of the child are actively involved in supporting the child’s development ESDM focuses on helping the child learn and grow by engaging them in activities that they truly enjoy, such as playing or daily activities.

Speech therapy not only helps in the development of nonverbal and verbal communication skills but also alternative communication skills with the use of pictures or technology.

A speech therapist would be capable of identifying alternative augmentative communication (AAC), such as the picture exchange communication system (PECS), sign language, speech output devices, etc, and use these to aid in the development of verbal communication in autistic children.

These are only some of the many intervention programs available for autism. An autistic child’s needs are unique and therefore it's essential to tailor intervention programs to meet their specific needs.

Some of the other treatment programs for ASD are:

  • DIR/Floortime approach
  • TEACCH (Treatment and Education of Autistic and related Communication handicapped Children)
  • Sensory Integration Therapy
  • Social Skills Training

Myths and Facts about Autism

There is no doubt that there are a lot of misconceptions about autism spectrum disorder. In order to cater for the needs and support of autistic people, it is important to dispel misinformation and have accurate information about what autism is.

Myth: Girls don't get autism

Fact: While the prevalence of autism in boys is four times more likely than in girls, this does not mean that girls cannot develop autism. Moreover, misdiagnosis is more common in girls with autism than in boys.

Myth: The environment these days is leading to autism

Fact: While it is true that autism is more commonly being diagnosed than it once was, other factors are responsible for this. Firstly, the awareness surrounding this disorder has increased, which is more likely the cause of increased diagnosis. Secondly, the way we describe children with autism has changed.

Now, autism includes various conditions like autism disorder, pervasive developmental disorder, and Asperger’s syndrome. All of these have been combined under the spectrum of ASD, rather than being separate disorders.

Myth: Only children can be diagnosed with autism

Fact: No. As the understanding of the condition improves amongst the general population, more people are being diagnosed with ASD in adulthood. Some children who were misdiagnosed with ADHD, anxiety or stress in their childhood because the doctors could not recognise the ASD symptoms are more likely to receive their ASD diagnosis in adulthood, today.

General Queries About Autism

Do vaccines cause Autism?

No, vaccines are not linked to autism. One of the reasons this misunderstanding arises is because the age at which the traits of autism begin to develop coincides with a child’s vaccination schedule.

Is Autism genetic?

If you have an autistic child, the chances of you having another autistic child are high. Research shows that 60 to 90% of the risk of autism comes from one’s genome (Tick et, al., 2016).

A high risk for autism is also linked to genetic disorders like Fragile X syndrome or Rett syndrome

How can I help an Autistic child at home?

Parenting and taking care of an autistic child comes with a special set of responsibilities. One of the ways you can help an autistic child at home is by integrating sensory activities. They play a crucial role in helping an autistic child navigate and learn essential daily life skills.

Is autism curable?

Autism is a lifelong condition. Rather than cure, the primary goals for intervention and treatment programmes of autism are to minimise the disturbance in behaviour, reduce the symptoms and improve social and occupational functioning.

Contact us

We would love to help you and your child out in every way possible. Fill out the form and lets start a beautiful journey.

I have read and agree to Terms and Conditions and the Privacy Policy.