SEED began in 2007 as one of the largest studies of young children, aged between 2 and 5 years, with Autism Spectrum Disorder (ASD) in the United States. The study looks at their risk factors for ASD and developmental characteristics. In 2021, SEED was expanded to learn more about the health, functioning, and needs of people with ASD and other developmental disabilities as they mature into adolescence and adulthood. Potential participants had to have received an ASD or related diagnosis (e.g., conduct disorder, intellectual disability, or significant developmental delay) from a clinical provider, or received early intervention or special education services for an ASD or related condition (e.g., intellectual disability or severe emotional disorder). SEED has more than 8,000 total participants, made up of over 2,000 children with ASD (81% males with ASD, 19% females with ASD), more than 3,000 children with other developmental disabilities, and more than 3,000 children from the general population.

Recruitment is ongoing