What is autism?
Autism is a complex developmental disability that causes problems with social interaction and communication. Symptoms usually start before age three and can cause delays or problems in many different skills that develop from infancy to adulthood. Autism is one of a group of serious developmental problems called Autism Spectrum Disorders (ASD) that appear in early childhood — usually before age 3. Though symptoms and severity vary, all autism disorders affect a child’s ability to communicate and interact with others.
What is an autism spectrum disorder?
Different people with autism can have very different symptoms. Health care providers think of autism as a “spectrum” disorder, a group of disorders with similar features. One person may have mild symptoms, while another may have serious symptoms. But they both have an autism spectrum disorder. (Source)
Asperger Syndrome: Asperger’s syndrome is a developmental disorder that affects a person’s ability to socialize and communicate effectively with others. Children with Asperger’s syndrome typically exhibit social awkwardness and an all-absorbing interest in specific topics. Doctors group Asperger’s syndrome with other conditions that are called autistic spectrum disorders or pervasive developmental disorders. These disorders all involve problems with social skills and communication. Asperger’s syndrome is generally thought to be at the milder end of this spectrum. (Source)
Childhood Disintegrative Disorder: Childhood disintegrative disorder, also known as Heller’s syndrome, is a condition in which children develop normally until ages 2 to 4, but then demonstrate a severe loss of social, communication and other skills. Childhood disintegrative disorder is very much like autism. Both are among the group of disorders known as pervasive developmental disorders, or autism spectrum disorders. And both involve normal development followed by significant loss of language, social, play and motor skills. However, childhood disintegrative disorder typically occurs later than autism and involves a more dramatic loss of skills. In addition, childhood disintegrative disorder is far less common than autism. (Source)
Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS): PDD-NOS stands for Pervasive Developmental Disorder-Not Otherwise Specified. Psychologists and psychiatrists sometimes use the term “pervasive developmental disorders” and “autism spectrum disorders” (ASD) interchangeably. As such, PDD-NOS became the diagnosis applied to children or adults who are on the autism spectrum but do not fully meet the criteria for another ASD such as autistic disorder (sometimes called “classic” autism) or Asperger Syndrome. (Source)
Rett Syndrome: Rett syndrome is a rare genetic disorder that affects the way the brain develops. It occurs almost exclusively in girls. Most babies with Rett syndrome develop normally at first, but symptoms start to surface after 6 months of age. Over time, children with Rett syndrome have increasing problems with movement, coordination and communication that may affect their ability to use their hands, communicate and walk. (Source)