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"How many forms of autism exist?"


I know of a few. Are there a lot?


Autism and related disorders are a set of developmental disorders that affect multiple domains of neuropsychological functioning. The major domains of function typically affected in autism are communication, behavior, and socialization. There are several disorders that affect these domains of functioning, including autistic disorder (also know as classic autism or Kanner's autism), Rett disorder, Asperger disorder, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified (PDD-NOS, aka atypical autism).

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Most of these disorders were originally identified and characterized separately, but upon further study it became clear that although there is some heterogeneity among these disorders, they all fall somewhere in a "spectrum" of autistic disease. It is for this reason that the psychiatric community often refers this group of illnesses as "autism spectrum disorders" and has classified them in such a way that they all fall under the umbrella diagnosis Pervasive Developmental Disorder. Autistic disorder, or classic autism, is a developmental disorder characterized by impairment in reciprocal social interaction, impairments in communication (including delay in spoken language), restricted or stereotyped behavior (including preoccupation with certain specific interests, routines, and rituals), and onset of at least one of these deficits or delays prior to three years of age. Rett disorder is a developmental disorder caused by mutations in the MECP2 gene. It occurs almost exclusively in females and is characterized by an initial period of normal development, followed by gradual loss of previously attained developmental milestones including loss of speech and purposeful hand use. Patients with Rett syndrome display stereotypic hand movement, deceleration of head growth, seizures, and autistic behavioral features. Asperger disorder is similar to high functioning classic autism in many ways, but individuals with Asperger disorder generally have much higher levels of cognitive function and have significantly better acquisition of language than those affected by classic autism. Childhood disintegrative disorder is a rare developmental disorder on the autism spectrum where children develop normally for a period of at least 2 years, followed by loss of previously acquired verbal, social, behavioral, and motor skills. After the regression of developmental skills occurs, the pattern of disease in childhood disintegrative disorder is essentially identical to that of autism. Pervasive developmental disorder not otherwise specified, or atypical autism, is a diagnosis applied to individuals who meet some but not all of the criteria for other well recognized autism spectrum disorders. All the autism spectrum disorders are serious developmental disorders that leave those affected with varying degrees of impaired social, behavioral, verbal, and motor functioning. Children and adults with autism require special care and therapy by specialists such as psychiatrists, behavioral therapists, and special educators. If you believe a child or someone else you care for has autism, please make an appointment for a full evaluation with a child or general psychiatrist.

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