Intellectual disability (ID) is impaired development of learning, reasoning, social, and life skills. It often becomes apparent at birth or during childhood and continues through adulthood. This condition occurs in varying degrees and can result from genetic, environmental, or unknown factors.
For many decades, the medical establishment and the general public unkindly referred to affected individuals as “feeble-minded,” “moron,” “idiot,” and “imbecile.” During the 1960s, the American Association on Intellectual and Developmental Disabilities (AAIDD) and lawmakers adopted the term “mentally retarded,” which experts considered to be more sensitive at the time.
The term “intellectual disability” came about because of Rosa’s Law, passed in 2010 and named after a young girl with ID.
This article reviews ID, its causes, diagnosis, and related conditions. It also offers coping tips for parents.
Intellectual disability is “a disability characterized by significant limitations in both intellectual functioning and in adaptive behavior” (being able to cope in one’s environment).
When someone has an intellectual disability, they have limitations in their ability to learn, practice good judgment, and problem-solve (intellectual functioning); they may have difficulty communicating or be unable to live independently.
In some cases, individuals may not show signs of ID in early childhood but develop symptoms during adolescence or adulthood.
Intellectual disability is the most common developmental disability. Approximately 439,000 affected children and youth ages 3 to 21 received support under the Individuals with Disabilities Education Act (IDEA) in 2019. However, the number of affected children could be higher because data were unavailable for some states.
Children with disabilities may experience issues with:
Some children may always require assistance with these activities.
The life expectancy of adults with intellectual disabilities has increased over recent decades. For these people, aging comes with additional health risks compared to their peers because they are at higher risk of developing certain health conditions at an earlier age.
These health conditions include:
They also face discrimination and exclusion, which trigger secondary mental health disorders, such as anxiety and depression. Nevertheless, many adults with mild intellectual disabilities can thrive on their own or with minimal support.
ID can be caused by a variety of factors, including injury, disease, or an issue with brain development. Chromosomal defects such as variants and inborn errors of metabolism can permanently alter cognitive function.
Intellectual disabilities arise from factors such as:
Intellectual and developmental disabilities also stem from cognitive disruption due to:
Pediatricians and other child healthcare providers can screen for IDDs at your well-child visits and annual exams. You might complete a brief, standardized test that your pediatrician will score. A medical professional may interview you and observe your child for symptoms as well.
Gold-standard tests for intellectual disability include the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview, Revised.
In some cases, a chromosomal microarray analysis (CMA) or the array comparative genomic hybridization (aCGH) test is used to pinpoint genetic mutations. These tests are usually done by taking a small blood sample but sometimes saliva or skin tissue is also used for a CMA.
Overall, intellectual disability is identified by problems in both intellectual and adaptive functioning, as such:
The AAIDD uses the Supports Intensity Scale (SIS) to assess the severity of ID. It focuses on the types of supports an individual requires to thrive, not just the limitations of the mentally challenged, and ranks them as follows:
Intellectual disability frequently co-occurs with other developmental, physical, medical, and psychiatric conditions. It can be challenging to identify these illnesses if the affected person has limited communication skills. Commonly related conditions include:
Other conditions associated with intellectual disability include:
Both children and adults with intellectual disabilities need support.
Ways to support children with ID include the following:
Your pediatrician and local school can be your partner in caring for your child with ID. Federal laws provide for special education and accommodations in public schools. You can ask for an evaluation to determine your child’s needs and help develop an Individualized Education Program (IEP) for a successful learning journey.
