Autism comprises a wide spectrum of disorders and affects an estimated one in every 150 children. Autism is a form of pervasive developmental disorder (PDD).
Autism Spectrum Disorder (ASD)
Pervasive Developmental Disorder (PDD)
Autism comprises a wide spectrum of disorders and affects an estimated one in every 150 children. No two people with an autism spectrum disorder are alike, but they do have many similar traits and challenges, and overall, autism implies an impaired ability to read and manage social cues.
Autism is a form of pervasive developmental disorder (PDD) and is part of a group of disorders characterized by delays in socialization, communication, language and motor skills and repetitive stereotype behaviors. Other types of PDD include Asperger's Syndrome, Childhood Disintegrative Disorder, Rett's Syndrome and PDD-NOS (pervasive developmental disorder not otherwise specified).
Children with PDD vary widely in abilities, intelligence, and behaviors. Some children do not speak at all, others speak in limited phrases or conversations, and some have normal language development. Repetitive play skills and limited social skills are generally evident in all. Unusual responses to sensory information, such as loud noises and lights, are also common. The spectrum of autism has such a broad diagnosis that it can include people with very high IQ's and those with severe mental retardation.
Parents are usually the first to notice unusual behaviors in their child and in some cases, a baby seems ‘different’ from birth, and signs point to autism and an early diagnosis can be made. Other times, a child who has been developing normally, suddenly becomes silent and withdrawn and the parent senses something is wrong although they may not realize the specific nature of the problem. Only 50 percent of children are diagnosed before kindergarten. Early intervention is so important because it has a dramatic impact on reducing symptoms and increasing a child's ability to learn new skills.
Pervasive developmental disorders range from the most severe form called autistic disorder to a milder form known as Asperger's Syndrome. When children have symptoms of either of these disorders but do not meet the specific criteria for either, they are diagnosed as having Pervasive developmental disorder not otherwise specified (PDD-NOS).
Other rare, severe disorders included in the autism spectrum disorder is Rett syndrome and childhood disintegrative disorder. Rett syndrome affects exclusively females and is found in approximately one in every 15,000. With this condition, the little girl's development is normal until somewhere between 6 and 18 months when autism-like symptoms begin to appear and she regresses. She loses her ability to talk, cannot control her feet and wrings her hands constantly during awake time.
The other rare disease, childhood disintegrative disorder (CDD),occurs in fewer than two children per 100,000 children with autism spectrum disorder. It affects mostly males and symptoms appear by the age of two, but the average age of onset is between 3 and 4 years of age. Before this, the child has normal development. This long period of normal development is what helps distinguish CDD from Rett syndrome. The loss of vocabulary and other skills is more dramatic than in autism. CDD is also accompanied by loss of bladder and bowel control, seizures and a very low IQ.
There are many theories on the cause or causes of autism spectrum disorder including genetics, brain structure, immunizations, and environmental impacts but there is no agreement at this time and research is ongoing.
