about IDDs

Intellectual and developmental disabilities (IDDs) are a group of disabilities that begin at birth or in childhood that can affect a person’s intellectual, physical and emotional development. People with IDDs can have challenges with both intellectual functioning and adaptive behaviors, which are everyday life skills like self-care, communication and social interaction.

People can have mild, moderate or severe IDDs. The most common causes are genetics, problems during pregnancy or childbirth, and childhood illness – but the cause of IDD is unknown in most cases.

What Conditions Fall Under IDD?

IDD is a term that encompasses a variety of diagnoses. While some IDDs have physical signs and symptoms, others can be invisible to the eye. Some of the most common ones are:

Autism spectrum disorder
Down syndrome
Fetal alcohol spectrum disorder
Fragile X syndrome

How Prevalent are IDDs?

IDDs can happen in any family. There are no racial, educational, social or economic boundaries when it comes to IDDs. An estimated 6.5 million Americans have an intellectual or developmental disability, and approximately 1-3 percent of the global population is affected – or as many as 200 million people.

What Limitations Do People with IDDs Have?

People with IDDs are like everyone else – they have unique interests, values and personalities. They cherish their family and friends, and they are capable of contributing to the community.

The abilities of people with IDDs can vary greatly. About 85 percent of people with IDDs have a mild form and can succeed in school and work. However, in more severe cases, they may only be able to communicate on a basic level.

What Language and Terms Should You Use?

Language is an important part of acceptance and understanding. Experts in the IDD community have outlined terminology that ensures people with IDDs are treated with individuality and dignity. Some of the best practices include:

Use “people-first language.” This means you refer to a person with IDD rather than an “intellectually disabled person.”
Avoid saying a person is “suffering from,” “a victim of” or “afflicted with” an IDD.
Avoid the word “unfortunate” when referring to a person with IDD.
When discussing IDDs, people without one are referred to as “typical,” rather than normal.