Behavioral questionnaires to help diagnose autism

Behavioral questionnaires are commonly used to help identify autistic behaviors and to evaluate their severity. The specific test used varies depending on the health professional's preference and the child's symptoms. Commonly used assessments include the following.

• Modified Checklist for Autism in Toddlers (M-CHAT). This test is used to evaluate infants who are at least 24 months old. The M-CHAT is better than the original CHAT (Checklist for Autism in Toddlers) for detecting autism. The test continues to be studied to identify milder autistic symptoms.
• Pervasive Developmental Disorder Screening. This questionnaire is completed by parents to evaluate early signs of autism.
• Autism Screening Questionnaire. This test is for children 4 years of age and older.
• Autism Behavior Checklist. This is a screening tool completed by the child's teacher.
• Childhood Autism Rating Scale. This test rates how much a child's behavior varies from that of other children the same age (older than 24 months).
• Autism Diagnostic Interview. Parents provide information about their child's behaviors during this wide-ranging, structured interview.
• Autism Observation Schedule. During this test, a health professional observes a child as he or she performs several activities involving communication, social interaction, play, interests, and other behaviors.