Intellectual Development Disorder Basics

Children with intellectual development disorder (IDD) have deficits in general intellectual functioning. They struggle with skills like reasoning, planning, judgment, thinking abstractly and many types of learning. Our guide explores the signs of IDD and how it is diagnosed.

IDD: What Is It?

Intellectual development disorder (IDD) is a neuro-developmental disorder characterized by deficits in general intellectual functioning such as reasoning, planning, judgment, abstract thinking, academic learning and experiential learning. These may also lead to impairments in practical, social and academic functioning. The symptoms of intellectual development disorder, a relatively new disorder, formerly fell under the umbrella of “mental retardation.”

IDD: What to Look For

Children with intellectual development disorder learn more slowly than typically developing children. These learning deficits generally apply to many kinds of learning and across different developmental stages. Young children with the disorder may learn to sit up, crawl, walk or talk later than other children. Most have difficulties developing communication skills as well as trouble interpreting and applying new information. These children often have trouble keeping up in school.

Older children with intellectual development disorder may demonstrate deficits in memory, social, and problem-solving skills. A lack of social inhibitions may also be a sign that a child has this disorder—not because the child is “acting out” or “rebelling,” but because he has difficulties interpreting the signs as to what kinds of behavior are appropriate in a given situation.

Children with intellectual development disorder often have difficulty with adaptive skills, or tasks of daily living, that typically children do not experience.

IDD: Risk Factors

Risk factors include genetic syndromes, brain malformations, environmental influences like alcohol or toxins, labor and delivery-related issues, traumatic brain injury, infections, seizure disorders, social deprivation, and more.

IDD: Diagnosis

Standardized tests such as an IQ test are used to determine a child’s level of intellectual development. A score below 70 on a standardized IQ test indicates that he may have intellectual development disorder. To be officially diagnosed, one must also exhibit deficiencies in two or more specific areas of adaptive behavior, such as communication skills, interpersonal skills, or daily living skills like getting dressed and using the bathroom. The onset of intellectual development disorder is usually before birth unless it is accounted for by a specific injury or toxic exposure before the age of 18.

IDD: Treatment

Intellectual development disorder is a lifelong disorder. It is treated through management and rehabilitation programs (including special education programs) aimed at helping children with the disorder acquire adaptive skills so they can live healthy, happy, relatively independent lives.