Autism, also known as autism or autistic disorder, is a representative disease of pervasive developmental disorder (PDD). DSM-IV-TR classifies PDD into five types: loneliness disorder, Retts syndrome, childhood disintegration disorder, Asperger syndrome and unspecified PDD.

Among them, loneliness disorder and Asperger syndrome are more common. There are different reports on the prevalence of autism, which is generally considered to be about 20 ~ 50/10,000 children, and the ratio of male to female is about1:3 ~1:4. The symptoms of girls are generally more serious than those of boys.

Extended data:

Autistic patients show various forms of conservative or restrictive behavior, among which the revised version of the Conservative Behavior Scale (RBS-R) is classified as follows.

1, strictly conservative movements, self-stimulation's behavior, unwillingness to change, such as slapping with hands, shaking head, or swinging body.

2. Coercive behavior, such as arranging objects to be stacked or linear, or forcing people to accommodate, etc.

3. Similarity is a resistance to behavior changes, such as insisting on not moving furniture or refusing to be interrupted.

4. Ritual behavior involves a pattern of unwillingness to change habits, especially things you like, such as unwillingness to change your mouth, or unwillingness to transfer to another school. This is closely related to similarity, and it has been suggested to merge these two items.

5. Restrictive behavior includes the limitation and narrowness of interest, concentration or activity, continuous concentration on certain parts of objects, such as wheels, etc., and the degree of attention to interested objects/things is abnormal compared with normal people.

6. Self-harm includes actions that hurt yourself or may hurt others, such as poking your eyes, pinching your skin, biting your hands or hitting your head.

References:

Baidu encyclopedia autism