Autism A complex condition, autism is the most commonly diagnosed pervasive developmental disorder.Autism impairs a person’s ability to communicate, both verbally and non-verbally, to form relationships and to interact with others. It also typically results in a range of unusual and repetitive behaviors. A child with autism may initially appear to develop normally, but then withdraw and lose interest in others.
Typically diagnosed by the time a child is age 3 or 4, autism can vary from mild to severe. Autism is frequently accompanied by mental retardation, but not always. In many cases, patients will show uneven levels of intelligence with highly developed talents in some areas.