A syndrome similar to Autistic Psychopathy characterised by severe and sustained impairment in social interaction, development of restricted and repetitive patterns of behavior, interests, and activities. These characteristics result in clinically significant impairment in social, occupational, or other important areas of functioning. In contrast to Autistic disorder (Autism), there are no clinically significant delays in language or cognition or self help skills or in adaptive behavior, other than social interaction.