The PDD Behavior Inventory: a rating scale for assessing response to intervention in children with pervasive developmental disorder.

The PDD Behavior Inventory (PDDBI) is a rating scale filled out by caregivers or teachers that was designed to assess children having a Pervasive Developmental Disorder (PDD; autism, Asperger disorder, PDD-NOS, or childhood disintegrative disorder). Both adaptive and maladaptive behaviors are assessed in the scale, making it useful for treatment studies in which decreases in maladaptive behaviors and improvements in adaptive social and language skills relevant to PDD are expected. The adaptive behaviors assessed include core features of the disorder such as joint attention skills, pretend play, and referential gesture. The maladaptive behaviors sample a wide variety of behaviors observed in both lower- and higher-functioning individuals and include stereotyped behaviors, fears, aggression, social interaction deficits, and aberrant language. The inventory was found to have a high degree of internal consistency. Inter-rater reliability was better for adaptive behaviors than for maladaptive behaviors. Factor analyses confirmed the structure of the PDDBI and indicated good construct validity. In a subsample of children between 3 and 6 years of age, raw scores for adaptive behaviors increased with age in the parent and teacher versions, as did measures of social pragmatic problems. It was concluded that the PDDBI is both reliable and valid and is useful in providing information not typically available in most instruments used to assess children with PDD.