How to Diagnose Autism


Autism is defined as a neurodevelopmental disorder that affects the social and behavioral aspects of patients, mostly children. Since it is a behavioral disorder, often the symptoms of one child or adult who is suffering from autism can differ from another. This makes it difficult to pinpoint exact, precise symptoms of the disease as there are a number of signs that differ from patient to patient and can be seen in one and absent in another. This further aggravates the process of making a diagnosis for the disorder.


How to diagnose autism

Because it is difficult to diagnose autism in the absence of any medical test, such as a blood test, the American Academy of Pediatrics has recommended that doctors screen children for autism during their regular visits. This will help identify whether the child has crossed all his or her developmental milestones or not and aids to diagnose the disease at a very early stage (sometimes even at the age of 18 months). The advantage of early detection is to make sure the child gets timely and complete treatment.


There are two steps involved in diagnosing autism spectrum disorder, or ASD, which include:

  • Developmental screening or behavioral assessment
  • Comprehensive diagnostic evaluation or physical assessment including medical tests


Behavioral assessment

  • The medical history of the child is assessed via a questionnaire about the child’s basic development. The questions include information regarding how a child points to objects to show his or her parents. An autistic child generally points at things, but does not check if his or her parents are looking at the object.
  • Similar observations are made following a guideline provided to check for any risks or symptoms.
  • Developmental delays in the child are observed and further evaluated to rule out any other medical conditions. This is followed by an intelligence test to see if thinking ability is affected by the developmental delay.


Laboratory tests and physical assessments

  • Physical tests of the child are carried out to examine the weight, height, and head circumference and evaluate whether they follow normal growth patterns.
  • Hearing tests are also conducted to determine whether developmental delay, such as use of language and social skills, is due to hearing loss.
  • A test for lead poisoning, especially a condition called pica, in which kids crave old paint or dirt even after passing the age when this stage is seen during their development.
  • Chromosomal analysis is carried out to check for intellectual disability, such as fragile X syndrome, and also to determine whether there is a family history of intellectual disability.
  • An EEG or electroencephalograph is done if developmental regression and seizures are witnessed.
  • An MRI is also carried out to check for any signs that point to differences in the brain structure.

The basic developmental assessment of all children must be carried out when they are 9 months old, 18 months old, and 24 months or 30 months old. Additionally, screening specifically for autism during regular doctor visits must be carried out at 18 and 24 months of age.


These evaluations can help make a diagnosis at a very early stage and provide the full potency of the treatment.