1. Autism: Involves difficulty in social communication and repetitive actions.
2. Asperger Syndrome: Causes delay in information processing procedure in brain and language development.
3. Pervasive Developmental Disorder: It is diagnosed when the criteria defining autism and asperger syndrome are not met.
Various factors have been pointed out as the possible causes of autism, mainly environmental atmosphere before birth like presence of heavy metal, pesticides, childhood vaccines etc have been held responsible for causing it, although most of them lack any scientific basis. Symptoms associated with autism begin to manifest themselves as early as the sixth month of the child, but keep developing as the child grows up, making full and steady appearance from the second year of it's life. In special cases, the child shows normal development in the early stage but then starts to regress. No curative measure for this disorder has been discovered yet, so there is a clamor for recognizing this disorder not as a disease, but as a difference.
Autistic symptoms make their presence known in the infants making them less attentive to a stimulus, reducing the possibility for them to respond to their own names and making them avoid eye contact, when interacting with others. These children are incapable of social understanding, spontaneous actions, expressing themselves through gestures, imitate and respond to emotions etc. Although these children do form attachment to their immediate caregivers, but they come to suffer more intense kind of solitude, as forming and maintaining friendship proves to be an arduous task for them. The obstacle they face while trying to communicate with others is caused by delayed language development, rendering them unable to talk and share experiences and making them merely repeat the words they hear from others.
Their obsession with repetitive patterns of behavior can be summarized in the following categories:
1. Stereotype indicates repetitive movements like rocking of body etc.
2. Compulsive pattern of behavior is adherence to some rules strictly like arranging things in a row.
3. Maintaining sameness involves strong resistance to change like their anger when a piece of furniture is moved.
4. Ritualistic behavior is closely associated with their obsession to maintain sameness like wearing the same dress everyday, which becomes a daily ritual.
5. Restricted behavior involves exhibiting very small range of interests, activities and focus.
6. Self injury: They also show a tendency to inflict injuries on themselves through head banging, skin picking etc. This is related to the aggressive and violent aspect of this disorder.
No cure has been discovered yet for his disorder. Many children with autism show notable improvements through long term treatment, although nobody knows how it happens, but some children do not show any improvement at all. These children can acquire language by the age of five or earlier, although in case of few, language development process gets delayed. The basic problems of autism continue, although the severity of their symptoms might diminish with the growing age of the individual. In exceptional cases, individuals with autism exhibits normal growth later in life and also become successful by finding proper or part time employment.