Autism spectrum disorder (ASD) is a range of complex neurodevelopment disorders characterized by:

Social impairments

As early as infancy, a baby with ASD may be unresponsive to people or focus intently on one item to the exclusion of others for long periods of time.

A child with ASD may appear to develop normally and then withdraw and become indifferent to social engagement.

Individuals with ASD have difficulty interpreting what others are thinking or feeling because they can’t understand social cues, such as tone of voice or facial expressions, and don’t watch other people’s faces for clues about appropriate behavior. They lack empathy.

• absence or impairment of imaginative and social play
• impaired ability to make friends with peers

Communication difficulties

Individuals with ASD tend to start speaking later than other children and may refer to themselves by name instead of “I” or “me.”

Children with ASD don’t know how to play interactively with other children.

Some speak in a sing-song voice about a narrow range of favorite topics, with little regard for the interests of the person to whom they are speaking.

• stereotyped, repetitive, or unusual use of language 
impaired ability to initiate or sustain a conversation with others

Repetitive • restricted • stereotyped patterns of behavior

Individuals with ASD may engage in repetitive movements such as rocking and twirling, or in self-abusive behavior such as biting or head-banging.

• restricted patterns of interest that are abnormal in intensity or focus
• inflexible adherence to specific routines or rituals
• preoccupation with certain objects or subjects