Per the National Institutes of Health, intellectual and developmental disabilities (IDDs) are disorders that are usually present at birth and impact a person’s physical, intellectual, and/or emotional development. Many of these conditions affect multiple systems.
Intellectual disabilities start any time before a child turns 18 and are characterized by their impact on both intellectual functioning and adaptive behavior, like social and life skills.
Developmental disabilities are a broader category of lifelong disabilities that can be intellectual, physical, or both.
The term “IDD” is often used to describe this community collectively. Sometimes the IDD community is also referred to as “neurodivergent,” meaning someone whose brain functions differently.
There a number of reasons that someone may have an IDD. For some people, an IDD could develop before birth, like Down syndrome. For others, an IDD can occur later in life as the result of traumatic brain injury. With other IDDs, like Autism, the cause is unknown. The most common causes of IDDs are: genetic conditions, complications during pregnancy or birth, and diseases or toxic exposure. IDDs are not contagious; you can’t catch one. They’re also not a mental illness, like depression, though people with an IDD may often have a “comorbid diagnosis,” meaning that they have two or more disorders or illnesses. For example, someone could have Autism and Obsessive- Compulsive Disorder; a person could be diagnosed with Cerebral Palsy as well as Depression. There are no cures for IDDs, but people with IDDs live full and happy lives. They may just approach things differently than people who are “neurotypical,” or people who do not have intellectual or developmental differences.
IDDs affect people differently. Each person experiences their IDD in a unique, personal way. Some people may need more support in certain areas of life than other people. Many people may have an IDD that presents more subtly. Even though their IDD may not be as apparent, it can still impact their daily lives.
It’s estimated that approximately 6.5 million people in the U.S. have an IDD. Globally, 1-3%, or as many as 200 million people, have an IDD.