Autism Spectrum Disorder (ASD)
Autism Spectrum Disorder (ASD) is a range of symptoms that are mostly characterized by impairment in social interactions, communication difficulties, and repetitive behaviors. ASD is typically diagnosed within the first two years of life and is first noticed when the child has difficulty with normal social interactions (like eye contact and communication) and they appear to withdraw from others. It is called a spectrum disorder because the severity and level of impairment in individuals can range from barely present to very severe.
The DSM-5 no longer has Asperger's disorder as a separate diagnosis. It is now included as a mild form within the Autism spectrum. There is widespread misconception that vaccines can cause an ASD - there is no scientific evidence to back this up. ASD is considered to be caused by both genetic and environmental factors.