A. Abnormal or impaired development is evident before the age of 3 years in at least one of the following areas:
- receptive or expressive language as used in social communication;
- the development of selective social attachments or of reciprocal social interaction;
- functional or symbolic play.
B. A total of at least six symptoms from (1), (2) and (3) must be present, with at least two from (1) and at least one from each of (2) and (3)
1. Qualitative impairment in social interaction are manifest in at least two of the following areas:
a. failure adequately to use eye-to-eye gaze, facial expression, body postures, and gestures to regulate social interaction;
b. failure to develop (in a manner appropriate to mental age, and despite ample opportunities) peer relationships that involve a mutual sharing of interests, activities and emotions;
c. lack of socio-emotional reciprocity as shown by an impaired or deviant response to other people’s emotions; or lack of modulation of behavior according to social context; or a weak integration of social, emotional, and communicative behaviors;
d. lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g. a lack of showing, bringing, or pointing out to other people objects of interest to the individual).
2. Qualitative abnormalities in communication as manifest in at least one of the following areas:
a. delay in or total lack of, development of spoken language that is not accompanied by an attempt to compensate through the use of gestures or mime as an alternative mode of communication (often preceded by a lack of communicative babbling);
b. relative failure to initiate or sustain conversational interchange (at whatever level of language skill is present), in which there is reciprocal responsiveness to the communications of the other person;
c. stereotyped and repetitive use of language or idiosyncratic use of words or phrases;
d. lack of varied spontaneous make-believe play or (when young) social imitative play
3. Restricted, repetitive, and stereotyped patterns of behavior, interests, and activities are manifested in at least one of the following:
a. An encompassing preoccupation with one or more stereotyped and restricted patterns of interest that are abnormal in content or focus; or one or more interests that are abnormal in their intensity and circumscribed nature though not in their content or focus;
b. Apparently compulsive adherence to specific, nonfunctional routines or rituals;
c. Stereotyped and repetitive motor mannerisms that involve either hand or finger flapping or twisting or complex whole body movements;
d. Preoccupations with part-objects of non-functional elements of play materials (such as their oder, the feel of their surface, or the noise or vibration they generate).
C. The clinical picture is not attributable to the other varieties of pervasive developmental disorders; specific development disorder of receptive language (F80.2) with secondary socio-emotional problems, reactive attachment disorder (F94.1) or disinhibited attachment disorder (F94.2); mental retardation (F70-F72) with some associated emotional or behavioral disorders; schizophrenia (F20.-) of unusually early onset; and Rett’s Syndrome (F84.12).
*World Health Organization. (1992). International classification of diseases: Diagnostic criteria for research (10th edition). Geneva, Switzerland: Author.
The complete ICD-10 description of Childhood Autism is available on pages 147-149 of The ICD-10 Classification of Mental and Behavioural Disorders: Diagnostic criteria for research.