Diagnosing Autistic Disorder

Autism is diagnosed when the patient meets the criteria in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition – Text Revision. At least six characteristics from the following three categories must be present, including at least two from the social interaction category and one each from the communication and patterns categories.

Social interaction
Patient displays impairment in social interaction, as shown by at least two of the following:

• marked impairment in the use of multiple nonverbal behaviors, such as eye-to-eye gaze, facial expression, body postures, and gestures to regulate social interaction
• failure to develop peer relationships appropriate to developmental level
• no spontaneous sharing of enjoyment, interests, or achievements with others
• lack of social or emotional reciprocity
• gross impairment in ability to make peer friendships.

Communication
Patient displays impairment in communication, as shown by at least one of the following:

• delay in or total lack of development of spoken language
• in individuals with adequate speech, marked impairment in initiating or sustaining a conversation with others
• stereotyped and repetitive use of language or idiosyncratic language
• lack of varied, spontaneous make-believe play or social imitative play appropriate to developmental level.

Patterns
Patient displays restricted, repetitive, and stereotyped patterns of behavior, interests, and activities, as manifested by at least one of the following:

• encompassing preoccupation with one or more stereotyped and restricted patterns of interest that’s abnormal either in intensity or focus
• apparently inflexible adherence to specific nonfunctional routines or rituals
• stereotyped and repetitive motor mannerisms
• persistent preoccupation with parts of objects.

Additional criteria
Patient displays delays or abnormal functioning in at least one of the following before age 3:

• social interaction
• language as used in social communication
• symbolic or imaginative play.

The disturbance isn’t better accounted for by Rett’s syndrome or childhood disintegrative disorder.