Pervasive developmental disorder not otherwise specified

Pervasive developmental disorder not otherwise specified (PDD-NOS) is a historic psychiatric diagnosis first defined in 1980 that has since been incorporated into autism spectrum disorder in the DSM-5 (2013). According to the earlier DSM-IV, PDD-NOS referred to "mild or severe pervasive deficits in the development of reciprocal social interaction and/or verbal and nonverbal communication skills, or when stereotyped behavior, interests, and/or activities are present, but the criteria are not met for a specific PDD" or for several other disorders. PDD-NOS was one of four disorders collapsed into the diagnosis of autism spectrum disorder in the DSM-5, and also was one of the five disorders classified as a pervasive developmental disorder (PDD) in the DSM-IV. The ICD-10 equivalents also became part of its definition of autism spectrum disorder, as of the ICD-11. PDD-NOS included atypical autism, a diagnosis defined in the ICD-10 for the case that the criteria for autistic disorder were not met because of late age of onset, or atypical symptomatology, or both of these. Even though PDD-NOS was considered milder than typical autism, this was not always true. While some characteristics may be milder, others may be more severe. 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 Uneven skill development (strengths in some areas and delays in others) Unusual play with toys and other objects Repetitive body movements or behavior patterns Preoccupation with fantasies that interfere and that are not normal to have at a certain age depending on social, cultural and religious norms. Unconventional perception of the world Maladaptive daydreaming, excessive daydreaming interfering with daily life PDD-NOS is not a current part of the Diagnostic and Statistical Manual of Mental Disorders typology (as of the DSM-5), which is the most common diagnostic typology used in the United States.