The following is from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM IV):

DIAGNOSTIC CRITERIA FOR 299.00 AUTISTIC DISORDER

A. A total of six (or more) items from (1), (2), and (3), with at least two from (1), and one each from (2) and (3)

• 1) qualitative impairment in social interaction, as manifested by at least two of the following:
  • a) marked impairments in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body posture, and gestures to regulate social interaction
  • b) failure to develop peer relationships appropriate to developmental level
  • c) a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people, (e.g., by a lack of showing, bringing, or pointing out objects of interest to other people)
  • d) lack of social or emotional reciprocity ( note: in the description, it gives the following as examples: not actively participating in simple social play or games, preferring solitary activities, or involving others in activities only as tools or "mechanical" aids )
• (2) qualitative impairments in communication as manifested by at least one of the following:
  • a) delay in, or total lack of, the development of spoken language (not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime)
  • b) in individuals with adequate speech, marked impairment in the ability to initiate or sustain a conversation with others
  • c) stereotyped and repetitive use of language or idiosyncratic language
  • d) lack of varied, spontaneous make-believe play or social imitative play appropriate to developmental level
• (3) restricted repetitive and stereotyped patterns of behavior, interests and activities, as manifested by at least two of the following:
  • a) encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus
  • b) apparently inflexible adherence to specific, nonfunctional routines or rituals
  • c) stereotyped and repetitive motor mannerisms (e.g. hand or finger flapping or twisting, or complex whole-body movements)
  • d) persistent preoccupation with parts of objects

B. Delays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years:

• (1) social interaction
• (2) language as used in social communication
• (3) symbolic or imaginative play

C. The disturbance is not better accounted for by Rett's Disorder or Childhood Disintegrative Disorder

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