PDD-NOS is an old diagnostic category. It is no longer included as an option for an Autism Spectrum Disorder and is not part of the DSM-5, but is included in theICD-10. The diagnosis of a pervasive developmental disorder not otherwise specified is given to individuals with difficulties in the areas of social interaction, communication, and/or stereotyped behavior patterns or interests, but who do not meet the full DSM-IV criteria for autism or another PDD. This does not necessarily mean that PDD-NOS is a milder disability than the other PDDs. It only means that individuals who receive this diagnosis do not meet the diagnostic criteria of the other PDDs, but that there is still a pervasive developmental disorder that affects the individual in the areas of communication, socialization and behavior. It is common for individuals with PDD-NOS to have more intact social skills and a lower level of intellectual deficit than individuals with other PDDs. Characteristics of many individuals with PDD-NOS are:
- Communication difficulties (e.g., using and understanding language).
- Difficulty with social behavior.
- Difficulty with changes in routines or environments.
- Uneven skill development (strengths in some areas and delays in others).
- Unusual play with toys and other objects.
- Repetitive body movements or behavior patterns.