There are five different types of Autism, or, more correctly, Pervasive Developmental Disorders (PDDs). These different types of autism have in common the inability of affected people to socialize, play or react appropriately to their environment.
The five different types of autism and their respective characteristics are:
(a) Classic autism: The most severe of any of the different types of autism, this causes its patients to have major problems in relating to other people or talking to them. Patients of classic autism may be hypersensitive to their environment; certain colors, sounds or textures can agitate them. Changes in routine can also upset them and they may prefer compulsive rituals like eating the same foods in the same order or watching the same TV show.
(b) Asperger's Syndrome: This is one the different types of autism that does not trigger any language delay but causes inadequate social and communication skills. An Asperger's syndrome patient may not understand social rules, can be awkward socially or may show a lack of empathy. They also make limited eye contact, usually have above-average intelligence but do not seem to be engaged in a conversation.
(c) Childhood Disintegrative Disorder: This is one of the different types of autism that may
develop in seemingly perfectly normal children. Between the age of 2 years and 4 years, these children may stop socializing, forget their potty-training and can even stop talking. They also no longer make friends, stop playing and lose their motor skills.
(d) Rett's Syndrome: This is one of the different types of autism that normally affects girls more and the child has poor growth of the head. The patient will exhibit repetitive hand movements like clapping, wringing the hands and excessive washing of hands. They may also have poor social and verbal skills and mental retardation is a common feature of this type of autism.