ICD-10 Diagnostic Criteria for Research - F84.3 - Other Childhood Disintegrative Disorder^*

A. An apparently normal development up to the age of at least two years.  The presence of normal age-appropriate skills in communication, social relationships, play, and adaptive behaviour at age two years or later is required for this diagnosis.

B. A definite loss of previously acquired skills at about the time of onset of the disorder.  The diagnosis requires a clinically significant loss of skills (and not just a failure to use them in certain situations) in at least two of the following areas:

1. expressive or receptive language;
2. play;
3. social skills or adaptive behaviour;
4. bowel or bladder control;
5. motor skills.

C. Qualitatively abnormal social functioning, manifest in at least two of the following areas:

1. qualitative abnormalities in reciprocal social interaction (of the type defined for autism);
2. qualitative abnormalities in communication (of the type defined for autism);
3. restricted, repetitive, and stereotyped patterns of behaviour, interests, and activities, including motor stereotypies and mannerisms;
4. a general loss of interest in objects and in the environment.

D. The disorder is not attributable to the other varieties of pervasive developmental disorder; acquired aphasia with epilepsy (F80.6); elective mutism (F94.0); schizophrenia (F20-F29); Rett's Syndrome (F84.2).

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