The term Pervasive Developmental Disorder is widely used by professionals to refer to children with autism and related disorders. The term can be confusing because "PDD" is not a specific diagnosis, but an umbrella term under which specific diagnoses are defined. Diagnosis of PDD, autism or any other developmental disability is based upon the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-4).
Diagnostic Criteria for Pervasive Developmental Disorder are as follows:
- Autistic Disorder (ASD) is complex neurobiological disorder that presents as a range of symptoms, especially communication disorders and impaired social interaction. Associated manifestations may include one or more repetitive and stereotyped patterns of behavior. Autism is a spectrum disorder, with symptoms ranging from mild to severe, and with the level of developmental delay unique to each individual.
- Asperger’s Disorder is defined by "severe and sustained impairment in social interaction and the development of restricted, repetitive patterns of behavior, interest and activity." In contrast to Autistic Disorder, there is no significant delay in language.
- Rett’s Disorder
- Childhood Disintegrative Disorder
- Pervasive Developmental Delay (PDD-NOS) is defined by "severe and pervasive impairment in the development of reciprocal social interaction or verbal and nonverbal communication skills; and stereotyped behaviors, interests and activities". The criteria for Autistic Disorder are not met because of late age onset; atypical and/or sub-threshold symptomotology."
According to the Autism Society of America, it is important to note that "whether a child is diagnosed with Autism Spectrum Disorder or PDD-NOS, his or her treatment will be similar".