There are many different symptoms of autism, and many of them can go unnoticed, particularly in the mild cases or in the situations where a more serious disease is also present. If a child is showing some of the signs below, it is recommended to ask for an expert opinion:

  • no baby talk or gesturing by the age of 12 months
  • no words at all by 16 months
  • no phrases of at least two words by 24 months
  • no reaction when his/hers name is called
  • total or partial lack of eye contact
  • compulsive behaviour, arranging object in lines
  • lack of smile and other expressions of empathy
  • any loss of already acquired skills

Symptoms that might appear later on:

  • difficulties in creating and maintaining friendships
  • difficulties to start or take part in a dialogue with somebody else
  • difficulties in developing social skills
  • poor or unusual use of languages, including stereotipies
  • uncommon interests of unusual intensity
  • intense preoccupation with specific objects or topics
  • precise following of ritual activities

There are questionnaires used by health care providers as an assessment method for the evolution of the children. Some screening techniques are based exclusively on the parents’ observations, while others are a combination of parents and doctors observations. When they reveal the possibility of an ASD disorder further investigation is recommended.

An in-depth evaluation is performed by a team of specialists from different fields. It usually involves a psychiatrist, a pediatric neuropsychologist, a speech development specialist, and possibly others. Thorough tests are performed, especially on the neurological condition and speech development.

Children with hearing problems or with visual impairments are more difficult to diagnose since an important part of the evaluation is influenced by the proper functioning of these senses.

When some of the typical symptoms of autism are missing the children might be diagnosed with PDD-NOS. If the language skills are developed normally but there are other indicators of autism the diagnosis can be Asperger syndrome.

There are some cases in which the child can be diagnosed with childhood disintegrative disorder that will later on evolve into a typical case of autism, but these situations are rarely met