There have been significant changes to the World Health Organisation’s ICD-11 disease classification for autism. It places all types of the problem under a single diagnostic category ‘autism spectrum disorder‘. This includes varieties of autism that were previously treated as separate clinical entities, namely:

  • infantile autism;
  • Asperger’s syndrome;
  • atypical autism;
  • other holistic developmental disorders.

To make the diagnosis more specific and better define the needs of the patient, additional information has been included in the new WHO classification. These relate to the type and severity of abnormalities in intellectual development and functional speech. For example, the clinical entity previously referred to as Asperger’s Syndrome will most likely be diagnosed as ‘autism spectrum disorder without intellectual developmental abnormalities and with or without mild functional language abnormalities’.

The above changes were prompted by specialists:

  • the results of research into the causes of ASD;
  • diagnostic difficulties related to the presence of entities with vague diagnostic criteria;
  • the finding of different symptoms in one person over several years of life, which entailed a change in diagnosis.

The term ‘autism spectrum disorder’ does not include Rett Syndrome. This – genetically determined – problem is characterised by distinct symptoms and course. It was therefore moved to a different diagnostic category.