Autism spectrum disorder (ASD) is an unbrella term for a group of complex disorders of brain development. It is often reffered to as Autism. Autism is NOT caused by anything you did or didn't do as a parent. While the real cause of Autism is still unknown, there is general agreement among the scientific community that the cause is biological, most likely neurological.
Autism or ASD is characterized, by a period of normal development (usually till 2 yrs of age) and then slowly losing the skills. Child will exhibit difficulties in social interaction, communication and shows repetitive behaviors. ASD can be associated with intellectual, sensory, motor, attention and physical health issues. Each child with ASD exhibit a unique combination of these difficulties at a varying degrees as well. Based on certain combination and degree, ASD is broadly classified into five types.
> Asperger's syndrome
> Pervasive Developmental Disorder (PDD)
> Rett Syndrome
> Childhood Disintegrative Disorder
A child is diagnosed with Autism when he/she exhibits all main characteristics of ASD, like difficulty in communication, social/emotional issues, repetitive behaviors. The intellectual ability of the child with autism may vary from very high IQ to intellectual disability.
Asperger's syndrome is also known as high functioning Autism. These children will not have any speech delay or any significant communication problem but have significant issues with social/emotional skills and obsessive focus on certain topics. They may have poor relationships and may get attention for their eccentric behaviors. These children are generally very intelligent.
Pervasive Developmental Disorder--Not Otherwise Specified (PDD NOS)
PDD is diagnosed when a child exhibits some features of autism but not all. For instance,if a child exhibits speech delay and certain repetitive behaviors--he would most likely get a diagnosis of PDD (NOS)
Rett Syndrome is a rare disorder. Unlike Autism, Rett syndrome is caused by specific gene mutation and seen more in girls. It comes under autism because of the normal period of development and regression in skills, stereotypic hand movements, language and social issues.
Childhood Disintegrative Disorder
Very rare disorder and regression onset is much later compared to other ASDs. They exhibit profound deficits across all developmental areas.