This section of the website contains information about the different types of autism - also known as autism spectrum conditions, autism spectrum disorders, ASDs or pervasive developmental disorders.
There are four main sub-types of autism recognised within the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, published by the American Psychiatric Association.
Rett syndrome is no longer considered to be a sub-type of autism, although individuals with Rett syndrome may display autistic-like symptoms.
However the fifth edition of Diagnostic and Statistical Manual of Mental Disorders, DSM-5, published in May 2013 eliminated the four sub-types listed above by dissolving them into one diagnosis called Autism Spectrum Disorder. According to the APA, this represents an effort to more accurately diagnose all individuals showing the signs of autism.
At present, the term 'autism' is sometimes used interchangeably with the term 'autism spectrum disorders' to mean any or all of the different forms of ASD. It is also sometimes used interchangeably with the term 'autistic disorder'.