No, it is not. Autism is a specific condition that is connected to problems with social interaction, communication and repetitive behaviour. As such, autism is just one form of ASD. Autism spectrum disorders also include Asperger's syndrome, childhood disintegrative disorder and pervasive developmental disorder. Until recently, Rett syndrome was thought of as a type of autism spectrum disorder by medical science, but this is now not counted as part of the spectrum because it is understood to be caused by a specific genetic mutation.