Intellectual disability (ID) is a disability that impairs learning, reasoning, social skills, and the development of life skills. It is often evident at birth or during early childhood and persists into adulthood. The disability occurs in different degrees and may be due to genetic, environmental, or unknown factors.
For decades, the medical community and the general public callously referred to people with mental retardation as “mentally handicapped,” “idiots,” “idiots,” “stupid,” etc. In the 1960s, the American Association on Intellectual and Developmental Disabilities (AAIDD) and lawmakers adopted the term “mentally retarded,” which experts at the time considered to be more sensitive.
The term “intellectually disabled” was coined by ROSA’s Law, which was passed in 2010 and named after a young girl with intellectual disabilities.
This article explains intellectual disability, its causes, diagnosis and associated symptoms, as well as providing coping tips for parents.
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What does intellectual disability mean?
Intellectual disability is “a disability characterized by significant limitations in both intellectual functioning and adaptive behavior (the ability to cope with one’s environment).”
People with intellectual disabilities have limitations in their learning ability, judgment, and problem-solving abilities (intellectual functioning), and may have difficulty communicating and living independently.
In some cases, signs of ID may not be present during childhood, but symptoms may appear during adolescence or adulthood.
Symptoms of intellectual disability in children
Intellectual disability is the most common developmental disability. In 2019, approximately 439,000 children and adolescents ages 3 to 21 with intellectual disabilities received assistance under the Individuals with Disabilities Education Act (IDEA). However, the number of affected children may be higher because data was not available for some states.
Children with disabilities may experience problems such as:
They may take longer to communicate, interact with peers, meet personal needs, and develop more slowly than their peers, walking, eating, dressing, and performing other daily functions.
Some children will always need help with these activities.
Symptoms of intellectual disability in adults
The life expectancy of adults with intellectual disabilities has increased in recent decades. For people with intellectual disabilities, ageing carries additional health risks as they are at higher risk of developing certain health conditions at a younger age than other people of their age.
These health conditions include:
Obesity Hyperlipidemia (high cholesterol) Diabetes Heart disease High blood pressure Stroke Deep vein thrombosis Vision and hearing impairment
They also face discrimination and exclusion, which leads to secondary mental disorders such as anxiety and depression. However, many adults with mild intellectual disabilities are able to thrive on their own or with minimal support.
Causes of Intellectual Disability
ID can be caused by a variety of factors, including injury, disease, and problems with brain development. Chromosomal defects, such as mutations and inborn errors of metabolism, can permanently alter cognitive function.
Intellectual disability may result from the following:
Down syndrome is the most common cause of intellectual disability in the United States. Fragile X syndrome is the most common congenital (present at birth) cause of intellectual disability. Fetal alcohol syndrome Dravet syndrome is a rare congenital cause of intellectual disability. Huntington’s disease is a genetic cause of later-onset intellectual disability. Congenital abnormalitiesPrenatal infections
Intellectual and developmental disabilities can also result from cognitive impairments caused by:
Brain malformations Prenatal exposure to toxins such as alcohol, drugs, or lead or mercury Brain damage due to maternal infection or problems during birth Prenatal or postnatal brain infection
How do you know if your child has an intellectual disability?
Symptoms of intellectual disability vary depending on its underlying cause and severity. In severe or profound cases, it is often evident soon after birth. In milder cases, symptoms of intellectual disability may include:
Reach developmental milestones such as sitting, crawling, and walking later than other children Have difficulty speaking clearly or not being able to speak at all Have difficulty learning at school
If you think your child may have an intellectual disability, talk to your child’s health care provider, who can refer you to a developmental pediatrician. Contact public schools and early intervention programs for information and support.
Diagnosis of Intellectual Disability
Your pediatrician or other children’s health care provider can test for IDD during well-child exams or annual checkups. You can take a simple standardized test that your pediatrician will score. Health care professionals may also interview you and observe your child for symptoms.
The gold standard tests for intellectual disability include the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview-Revised.
In some cases, chromosomal microarray analysis (CMA) or array comparative genomic hybridization (aCGH) tests are used to identify genetic mutations. These tests are usually done using a small blood sample, although saliva or skin tissue may also be used for CMA.
Assessment of intellectual and adaptive functioning
Overall, intellectual disability is identified by problems in both intellectual and adaptive functioning.
Intellectual functioning: According to the American Psychiatric Association, intellectual functioning includes “reasoning, problem solving, planning, abstract thinking, judgment, academic learning, and learning from experience.”
Measures of intellectual function
Intellectual functioning is measured by standardized tests that can determine an IQ score. An IQ test score of 70-75 indicates that an individual has limited intellectual functioning.
Adaptive functioning: This relates to the skills your child needs to live safely and responsibly. To assess functioning, clinicians evaluate behavior through questionnaires and observing the patient perform skills.
Measures of adaptive functioning
Adaptive functioning is measured in three areas:
Conceptual: This includes reading, arithmetic, writing, knowledge and memory. Social: This includes social skills, communication, the ability to follow rules, making and keeping friends. Practical: This includes the ability to live independently, take care of personal hygiene, hold a job, manage money and handle organizational tasks.
Severity Rating
The AAIDD assesses the severity of ID using the Support Intensity Scale (SIS), which focuses on the type of support an individual needs to thrive, not just the limitations of the mentally ill person, and ranks them as follows:
Mild to moderate intellectual disability: Most people with intellectual disabilities have mild disabilities. They tend to have slower cognitive abilities and daily living skills, but are able to live with minimal assistance. People with moderate intellectual disabilities can venture into familiar places and use basic life skills with a little more assistance. Severe intellectual disability: Symptoms of severe intellectual disability include significant developmental delays and limited communication skills. Individuals may be able to care for themselves and perform simple daily routines. However, they require supervision in social situations and require family or institutional care. Severe intellectual disability: People with severe intellectual disabilities usually have a congenital syndrome. They are unable to live independently and require close attention and assistance with self-care. These individuals often have medical problems and physical limitations.
Intellectual and developmental disabilities
Intellectual disability is a type of developmental disability (DD), which the U.S. Centers for Disease Control and Prevention (CDC) describes as a broader category of symptoms due to impairments in the physical, learning, language, or behavioral domains.
“IDD” refers to the co-occurrence of intellectual disability and other disabilities. Examples of intellectual and developmental disabilities include:
Associated symptoms
Intellectual disabilities often co-occur with other developmental, physical, medical and psychiatric disorders. These can be difficult to identify when the affected person has limited communication skills. Commonly associated disorders include:
Anxiety disorders and depression Autism spectrum disorders Cerebral palsy Defects in the heart, eyes, digestive tract and other organs Epilepsy (a neurological disorder that affects brain activity and causes seizures) Impulse control disorders
Other symptoms associated with intellectual disability include:
Support for people with intellectual disabilities
Both children and adults with intellectual disabilities need support.
Here’s how to support your child with ID:
Encourage your child with a mild to moderate intellectual disability to be responsible and independent. Give your child chores around the house and help him or her develop daily self-care skills as they are able. Break tasks into small steps and tell your child what to do, step-by-step, until the task is completed. Give your child frequent feedback. Praise your child when he or she does well and encourage them to develop their abilities. Read to your child and enjoy fun activities with him or her and other families. Find opportunities for social activities in the community (such as scouts, recreation center activities, sports, etc.) to help your child build social skills and have fun.
Your pediatrician and local schools can be partners in caring for your child with an intellectual disability. Federal law governs special education and support in public schools. They can order an evaluation to determine your child’s needs and help develop an Individualized Education Program (IEP) to set him or her up for academic success.
There are also ways to support adults with ID.
Use clear, concise language and speak slowly rather than loudly (unless they are hearing impaired). Treat them like people their age. Don’t talk down to them. Just like us, they love to joke, tease and provoke. Set boundaries. Don’t tolerate their bad behaviour, just as you wouldn’t tolerate someone without a learning disability. Ask if you can help before you take action and assume they need help. Consider appointing a “guardian” to make medical decisions through a legal document called a “durable power of attorney”. Help them learn skills such as cooking, banking, transportation, socialising, medical visits and work.
summary
Intellectual disability is characterized by impairments in intellectual and adaptive functioning. Symptoms typically appear during early childhood but may not appear until later in life. Causes include genetic defects, prenatal or postnatal illnesses, brain injury during birth, and prenatal exposure to alcohol, drugs, or toxins.
Most affected people have a mild intellectual disability, but the disability can become moderate, severe, or profound. Early detection and intervention can provide access to specialized services and improve the health of loved ones living with an intellectual disability.