Autism spectrum disorder (autism): Causes and symptoms

An autism spectrum disorder is a complex neurodevelopmental disorder in which a patient experiences problems with social interaction and communication and also has typical repetitive behaviors. Patients with this condition also prefer routine and predictable patterns. The condition, which mainly affects boys, develops before the age of three. It is best to make the diagnosis as quickly as possible so that a child and its parents can receive timely help and guidance. The treatment can consist of various therapies as well as medication. The doctor also treats other conditions and symptoms that may be present.

  • Synonyms of autism spectrum disorder
  • Classification of autism spectrum disorder
  • Epidemiology of ASD
  • Causes of Autistic Disorder
  • Risk factors of autism spectrum disorders
  • Diseases
  • Genes
  • Brain
  • Environmental factors
  • Other risk factors
  • Associated conditions
  • Symptoms: Social interaction, communication and behavior
  • Social interaction and communication
  • Behaviour
  • Savant syndrome
  • Routine
  • Unusual eating behavior
  • Diagnosis and examinations
  • Treatment of autism
  • Prognosis of an autism spectrum disorder


Synonyms of autism spectrum disorder

Some well-known synonyms for autism spectrum disorder (ASD) are:

  • autism
  • autistic disorder
  • autism spectrum disorder


Classification of autism spectrum disorder

Autism spectrum disorder is an umbrella term that takes into account a number of neurodevelopmental disorders. The American Psychiatric Association’s diagnostic guidelines, known as the Diagnostic and Statistical Manual of Mental Disorders (DSM-V), list the following disorders in the category of autism spectrum disorder:

  • Asperger syndrome (problems communicating)
  • disintegrative condition for children
  • unspecified developmental disorders


Epidemiology of ASD

In developed countries, as of 2017, approximately 1.5% of children suffer from autism. Boys are affected four to five times more often than girls. Finally, autism spectrum disorder affects individuals all over the world, regardless of race, culture or economic background.

Causes of Autistic Disorder

The causes of an autism spectrum disorder are not known as of October 2020. In ASD, information processing in the brain is affected because the functioning of certain nerve cells is altered. How this happens is not well understood in October 2020.

Risk factors of autism spectrum disorders


Fragile X syndrome and other genetic disorders, metabolic imbalances and a history of viral infections are risk factors for autism.


Researchers have identified several genes that may be associated with autism spectrum disorder. Sometimes these genes arise by spontaneously mutating (changing). In other cases, patients inherit these gene mutations.


Patients with autism spectrum disorder may also have changes in key areas of the brain responsible for speech and behavior.

Environmental factors

Environmental factors also play a role in the development of an autism spectrum disorder, although doctors have not yet demonstrated an effective proven link as of October 2020. Possible risk factors in pregnant women to give birth to a child with ASD are certain infections, such as rubella and toxins. , including valproic acid, alcohol, cocaine, pesticides, heavy metals and air pollution.

Other risk factors

Other risk factors for autism spectrum disorder include:

  • have an immediate family member with autism
  • low birth weight being born to older parents


Associated conditions

Autism spectrum disorder is associated with other medical conditions, such as epilepsy and tuberous sclerosis (neurocutaneous disorder with tumors). An estimated 20 to 30 percent of patients with autism spectrum disorder develop epilepsy by the time they reach childhood. Various metabolic defects, such as phenylketonuria (brain and body abnormalities), are also associated with autistic symptoms. Some other conditions are also often accompanied by an autism spectrum disorder, such as depression, anxiety disorders, intellectual disabilities, obsessive-compulsive disorder (OCD), sleep disorders and various genetic disorders.

Symptoms: Social interaction, communication and behavior

Some children with autism spectrum disorder appear to show symptoms from birth, while others only develop symptoms as they grow older. The symptoms of an autism spectrum disorder appear before the age of three and develop gradually. The term spectrum in autism spectrum disorder refers to the wide variety of symptoms and severity within autism spectrum disorder. Some patients with the condition experience debilitating social problems, while others may function more independently. The patient usually experiences severe limitations in social interactions and communication. He also exhibits limited, repetitive stereotypical patterns of behavior, interests, and activities.

Social interaction and communication

An autism spectrum disorder affects social interaction and communication:

  • as a baby, do not babble or coo at the parents
  • late speech development
  • not understanding gestures properly
  • do not understand spoken language well
  • not understanding facial expressions properly
  • difficulties understanding feelings and expressing their own feelings
  • difficulty understanding expressions (they often take this literally)
  • difficulty maintaining a conversation
  • don’t respond to their names
  • using unusual speech patterns, such as using a robotic tone
  • avoiding eye contact with others
  • often repeat sentences



In addition to impaired communication, a patient with an autism spectrum disorder also exhibits repetitive or unusual behavior.Examples of this are:

  • need for unchanging routine / resistance to change (such as same daily schedule, meal menu, clothing, route to school)
  • extreme interests in specific topics
  • being obsessed with a theme, such as cars, train schedules, or airplanes
  • repetitive movements of the body (such as rocking back and forth, clapping, twisting, running back and forth)
  • repetitive movements with objects (such as turning the wheels of a toy car)
  • ritual behavior (such as lining up objects, repeatedly touching objects in a fixed order)
  • staring at lights or rotating objects


Savant syndrome

About 1 in 10 patients with autism spectrum disorder show signs of savant syndrome, although this condition also occurs in patients with other developmental disorders or injuries to the nervous system. Savannah syndrome occurs when a patient exhibits extraordinary abilities in a particular area, such as playing a musical instrument, performing extremely complex calculations quickly, reading two pages of a book at the same time, or being able to remember large amounts of knowledge.


Patients with autism spectrum disorder need routine and predictable patterns. A break from routine or exposure to loud, overstimulating environments overloads a patient with autism spectrum disorder, leading to outbursts of anger, frustration, anxiety or sadness.

Unusual eating behavior

Unusual eating behavior occurs in approximately three-quarters of children with ASD, to the extent that it used to be a diagnostic indicator. Selectivity is the most common problem, although food refusal also occurs. This normally does not result in malnutrition.

Diagnosis and examinations

As of October 2020, there is no specific test for diagnosing an autism spectrum disorder. Doctors make a diagnosis through information from parents about the patient’s behavior and observation. It is also important to rule out other conditions. For example, if a child has undiagnosed hearing loss, the symptoms are sometimes similar to autism spectrum disorder.

Treatment of autism

As of October 2020, there is no cure for autism spectrum disorder. Furthermore, there is no one-size-fits-all treatment for autism spectrum disorder, as each patient with the condition presents differently. In some patients with autism spectrum disorder, medications and behavioral treatments improve the effects of the condition so that the patient is able to function independently in adulthood. Furthermore, applied behavior analysis (ABA), developmental models, structured teaching, speech and language therapy (speech therapy), social skills therapy, occupational therapy and various forms of communication support are often useful. Other patients require medical treatment for symptoms and other existing conditions, such as epilepsy.

Prognosis of an autism spectrum disorder

A combination of education about an autism spectrum disorder and early recognition of the signs results in early help for a child and its parents. This is important because prompt treatment improves the quality of life. Some patients with autism spectrum disorder live independently, while others require more long-term care and support.

read more

  • Asperger’s syndrome: Problems communicating
  • Savant syndrome: Condition with exceptional abilities