Definition of Autism Spectrum Disorder

The DSM-V characterizes autism spectrum disorders by 1) deficits in social communication and social interaction and 2) restricted repetitive behaviors, interests, and activities. Both components must be present for the diagnosis of an autism spectrum disorder. These impairments must be encapsulated by the following five criteria;

• Criterion A: social communication deficits, consisting of three items, all of which must be met to satisfy this criterion;
• Criterion B: fixated interests and repetitive behaviors consisting of four items, of which at least two must be met to satisfy this criterion;
• Criterion C: symptoms existing in early childhood;
• Criterion D: symptoms impairing functioning and
• Criterion E: impairments are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay

To diagnose ASD, all five criteria must be met. The DSM-V added severity of symptoms as: “very severe,” “severe,” “moderate,” or “mild” in the two domains; social communication and social interaction, and restricted repetitive behaviors. The severity formerly categorized as Aspergers is now on the mild end of the spectrum, while what was referred to as classic autism is on the opposite end.

The Individuals with Disabilities Education Act (IDEA) defines autism spectrum disorder (ASD) as “a developmental disability significantly affecting verbal and nonverbal communication and social interaction, generally evident before age three, that adversely affects a child’s educational performance. Other characteristics often associated with autism are engagement in repetitive activities and stereotyped movements, resistance to environmental change or change in daily routines, and unusual responses to sensory experiences.

The Centers for Disease Control (CDC) defines autism as “A developmental disability caused by differences in the brain. People with ASD often have problems with social communication and interaction, and restricted or repetitive behaviors or interests. People with ASD may also have diverse ways of learning, moving, or paying attention.”

The Autism Society of Minnesota (AM) defines autism as “a complex, lifelong developmental disability that affects essential human behaviors such as social interaction, the ability to communicate ideas and feelings, imagination, self-regulation, and the ability to establish relationships with others.”