Autism Spectrum Disorder – Symptoms, Causes, and Diagnosis

What is Autism spectrum disorder (ASD)?

Autism spectrum disorder (ASD) is a neurological and developmental disorder that affects people’s ability to interact, communicate, and socialize with others. Although autism can be diagnosed at any age, its symptoms generally appear in the first two years of life.

Individuals with autism spectrum disorder ASD are differently abled. The exact causes of the autism spectrum disorder are still unknown. Scientists believe there is more than one cause of ASD, acting together to change how most people develop. Moreover, most doctors and medical researchers believe ASD to be a hereditary disease. However, there is not enough evidence for this claim.


The broad spectrum of autism includes a variety of signs and symptoms, making it very hard to classify or distinguish ASD from other mental disorders. The abilities of people with ASD vary from person to person. Autism spectrum disorders consist of the following ailments:

  1. Asperger’s Syndrome

People suffering from Asperger’s syndrome tend to be smarter and more intelligent than normal individuals. However, they struggle with socializing and communicating with people. People with Asperger’s syndrome may be intelligent but struggle socially.

  1. Childhood Disintegrative Disorder:

Childhood disintegrative disorder, also known as Heller’s Syndrome, usually develops at 3-4 years. This disorder causes loss of previously acquired motor, social, and language skills.

  1. Autism spectrum disorder

ASD includes social, communication, and behavioral challenges. Major signs and symptoms of ASD usually begin to appear before the age of 3.

  1. Atypical Autism:

People with atypical autism have some classic autism symptoms, but not enough to consider it childhood autism or autism spectrum disorder.

What are the Signs and symptoms of Autism?

People with autism usually show signs and symptoms in their early childhood, at about 2 or 3 years of age. ASD symptoms may appear within the first 24 months of life in some children. While for others, symptoms may show at 24 months of age or later.

People with ASD often have difficulty communicating and interacting with others and may have restricted or repetitive behaviors. Autistic children usually show a wide range of symptoms. The frequency of occurrence and the intensity of these symptoms vary from person to person. Some have it mild, while some experience very intense symptoms. Moreover, every child with ASD has a unique behavioral pattern.

Because of the unique mixture of symptoms, it becomes difficult to determine the severity in each child. It generally depends on impairments and how they affect the individual’s capacity to function.

Some of the most common symptoms of autism spectrum disorder (ASD), with level and intensity varying for every individual, are

  1. Avoids eye contact
  2. Unresponsive to their name by nine months of age
  3. Indifference towards guardians
  4. Lack of language and communication skills
  5. Withdrawal or aggression
  6. Lack of ability to grasp or learn
  7. Lower (typical) intelligent level
  8. High level of (atypical) intelligence but with a lack of communication and socializing skills

What causes autism?

The reason and causes of autism are still unclear. All we know is that certain problems occur in some regions of the brain, affecting normal sensory functions. Autism is a complex disorder where symptoms and severity vary. There are several causes of autism affected by both genetic and environmental factors.

Even though the exact cause is not known, below given is a list of things that might cause autism.

  •  Inherited genetically
  • Children conceived by individuals of older age may be born with autism or a dominant combination of autism-causing genes.
  • Pregnant females with increased consumption of alcohol or certain medications.
  • Individuals suffering from phenylketonuria and rubella are also most likely to have autistic children.

Risk Factors

The number of children diagnosed with autism spectrum disorder is on the rise. Researchers are not sure if this is due to better identification and tests or a definite increase in the number of cases.

Autism affects children of all races and ethnicities, but certain factors predispose a child to this disorder. These may include:

  • Gender: Boys are four times more likely to have ASD than girls.
  • Family History: Genetics plays a huge role in autism. If a couple has a child diagnosed with ASD, there is a 20 percent greater risk for the next child to be autistic. Furthermore, if the first two children are diagnosed with ASD, the third child has a 32 percent risk of developing ASD.
  • Preterm Birth: Babies born before 26 weeks of pregnancy are more likely to develop ASD than full-term babies.
  • Other Disorders: Children with other disorders, such as fragile X syndrome, tuber sclerosis, and Rett syndrome, have a higher risk of developing ASD or autism-like symptoms.

Diagnosis of Autism

Doctors usually focus on signs, symptoms, and behavioral patterns to diagnose autism. People with autism show signs and symptoms in their early childhood, at about 2 or 3 years of age. The diagnosis for children usually includes:

  • Developmental screening test judging the basic patterns of behavior of the child
  • Hearing and vision tests
  • Genetic tests

If the above-given parameters suggest that an individual may be autistic, then the respective doctor recommends Autism Diagnostic Observation Schedule (ADOS) test. The child may be autistic if the test comes out to be positive.

How can autism be treated?

Autism spectrum disorder (ASD) is a lifelong disorder with no permanent cure. However, early diagnosis and treatment make a significant difference in the development and life of the individual with ASD. Therefore, it is necessary to consult a child psychologist when a child or an infant exhibits ASD signs and symptoms.

The two major treatments suggested for children showing signs of autism disorder are

1.   Applied Behaviour Analysis (ABA)

Applied Behaviour Analysis (ABA) helps with improving the following issues in autistic children. Aside from using medications to reduce symptoms of anxiety, ADHD, and hyperactivity, other therapy practices for autistic children include:

  • Behavioral and communication therapy
  • Occupational therapy
  • Sensory integration therapies
  • Speech therapy

2.   Complementary treatments

Other treatments include certain activities which help autistic children in learning how to communicate with people in their surroundings. These activities include encouraging them to learn art and music or engaging in physical activities like swimming, jumping on a trampoline, horse riding, etc.


Autism is called a ‘spectrum’ disorder because of the wide variation of the disorder’s symptoms and severity. It affects people across all genders, races, nationalities, and socio-economic groups, with boys having a higher prevalence than girls. ASD is a life-long disorder, but certain treatments and therapies can significantly improve symptoms and daily functioning. If you’re concerned as a parent, then it is necessary to contact your child’s healthcare provider at your earliest.

Scroll to Top