An Overview of Autism Spectrum Disorders

Autism is not simply one disorder: The word autism encompasses various degrees of neural development disorders. In simple terms, autism encompasses a spectrum of disorders. An individual can be said to have different degrees of autism. Many people are diagnosed as being “borderline” autistic. Because of this spectrum, and because there isn't a blood test or other sort of definitive test available, autism is not a simple diagnosis.

The autism spectrum (sometimes also called autism spectrum disorders or autism spectrum conditions), is a group of conditions on a spectrum characterized by difficulties in three areas: difficulties with communication, restricted interests, and repetitive behavior. Those who are considered "higher up" along the spectrum have more serious affects, and those "lower" on the spectrum have less debilitating affects.

The Spectrum

The autism spectrum has five different forms. Each form has a different level of influence on the affected individual and may have slightly different symptoms or affects:

Individuals can also be classified as “borderline” autistic, meaning they exhibit many of the symptoms of disorders within the autism spectrum, but to a much lesser degree then those with a clinical diagnosis of autism.

Autism

Classical autism forms the basis of the autism spectrum disorders. It is characterized by difficulties with social interaction, difficulties with communication, restricted interests and repetitive behavior. Individuals must meet all three criteria in order to receive a clinical diagnosis of autism. Some individuals with autism have been known to show unusual abilities, such as above-average memorization skills, and have even been known to be savants. Autistic individuals usually have trouble making and maintaining friendships or relating to others.

Asperger Syndrome

Individuals with Asperger syndrome generally lack nonverbal communication skills, posses limited empathy, and often exhibit a certain amount of physical clumsiness. The difference between autism and Asperger syndrome is that individuals with Asperger syndrome do not exhibit a significant delay in language development. Asperger syndrome is very similar to autism in its characteristic behaviors, symptoms, and likely causes.

Childhood Disintegrative Disorder

Childhood disintegrative disorder is very similar to autism in the evident impairment of social and communication skills, though the impairment is much more marked in childhood disintegrative disorder than it is in autism. It differs in other ways, as well. In childhood degenerative disorder, children develop normally until age two to four, after which they experience a decline in their social and communication skills. It is also less common than regular autism.

Rett syndrome

Rett syndrome occurs much more commonly in girls than in boys; it is very rare, occurring worldwide in one of every 10,000 to 23,000 female births. Rett syndrome is caused by mutations on the X chromosome, and these mutations can result in various affects, including the following:

  • Learning
  • Speech
  • Sensory sensations
  • Mood
  • Movement
  • Breathing
  • Cardiac function

Pervasive Developmental Disorder Not Otherwise Specified 

Also known as atypical autism, pervasive developmental disorder not otherwise specified (PDD-NOS) is the diagnosis given when the individual exhibits the signs and symptoms of the autism spectrum, but the criteria are not met for a specific disorder. Therefore, PDD-NOS covers the individuals who exist on the autistic spectrum, but are not classified as having either classical autism, Asperger syndrome, childhood disintegrative disorder, or Rett syndrome.

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