Accommodations Changes or adjustments that help meet a person’s individual needs.

Aggressive behavior Hostile or violent behavior, including hitting others, destroying property, or throwing tantrums. Aggression is among the most common challenges reported by parents of children and adolescents with autism.

Allergy A reaction by the immune system to something that does not bother most other people, such as certain foods, pollen or animals.

American Psychiatric Association An organization of psychiatrists working together to ensure humane care and effective treatment for all persons with mental illness.

Americans with Disabilities Act (ADA) U.S. law that ensures rights of persons with disabilities with regard to employment and other issues.

Angelman syndrome A genetic disorder causing developmental delays and neurological problems, often accompanied by seizures. Children often display hyperactivity, small head size, sleep disorders and movement and balance disorders.

Antecedent A verbal or physical stimulus, such as a command or request. The first in the three-step process used in Applied Behavior Analysis (ABA).

Anticonvulsant A type of drug used to prevent or stop seizures or convulsions; also called antiepileptic.

Anxiety Strong feelings of worry or fear about everyday activities. Anxiety disorder affects an estimated 30% of individuals with autism.

Applied Behavior Analysis (ABA) A style of teaching using series of trials to shape desired behavior or response. Skills are broken into small components and taught the individual through a system of reinforcement.

Asperger syndrome A developmental disorder, no longer used in the DSM-5, on the autism spectrum defined by impairments in communication and social development and by repetitive interests and behaviors, without a significant delay in language and cognitive development. The DSM-5 indicates that individuals with a “well-established diagnosis” of this condition “should be given the diagnosis of autism spectrum disorder.”

Assisted communication device A tool that helps you communicate with others. Examples include picture cards and electronic tablets that speak words that you type.

Attention deficit hyperactivity disorder (ADHD) A disorder that affects approximately 1 in 5 children with autism. Symptoms include chronic problems with inattention, impulsivity and hyperactivity.

Audiologist A professional who diagnoses and treats individuals with hearing loss or balance problems.

Augmentative and alternative communication (AAC) Methods of communication for people who can’t use speech (talking) to communicate; examples include sign language and using a computer for speech.

Autism Speaks Autism Treatment Network (ATN) A collaboration of Autism Speaks and some of the finest children’s hospitals and academic institutions in North America, specializing in multi-disciplinary medical care for children with autism.

Autism Spectrum Disorder (ASD) Also called autism. A condition characterized by a broad range of challenges with social skills, repetitive behaviors, and speech and nonverbal communication.

Autism-risk genes Specific genes that have been found to increase the risk of autism.

Autistic A term that many people who meet the criteria for ASD have adopted to describe their differences.


Babbling One of the first ways a baby communicates. Involves stringing together vowels and consonants such as “bababa” or “dadada”.

Baseline data Measurement of a behavior before an intervention is begun. Progress is measured by comparing current behavior to baseline data.

Behavioral intervention An intervention focused on increasing positive behavior and limiting challenging behavior, such as Applied Behavior Analysis.

Biomedical interventions A range of treatment methods that address underlying medical conditions and biological processes, such as the gastrointestinal system, diet and nutrition, immune function and sleep.