The American Association on Intellectual and Developmental Disabilities defines intellectual disability (ID) as the following:

  1. Substantial limitations in intellectual functioning
  2. Significantly limitations in adaptive behavior consisting of conceptual, social, and practical skills;
  3. Originating before age 18 ( AAIDD, 2008)
  4. Intellectual disability is concerned with IQ measures, intellectual functioning, language development and social behavior.

Click here to read more about mental retardation

Causes of intellectual disability

The most common causes of intellectual disability are:

  • Genetic conditions. These include things like Down syndrome and fragile X syndrome.

  • Problems during pregnancy. Things that can interfere with fetal brain development include alcohol or drug use, malnutrition, certain infections, or preeclampsia.

  • Problems during childbirth. Intellectual disability may result if a baby is deprived of oxygen during childbirth or born extremely premature.

  • Illness or injury. Infections like meningitis, whooping cough, or the measles can lead to intellectual disability. Severe head injury, near-drowning, extreme malnutrition, infections in the brain, exposure to toxic substances such as lead, and severe neglect or abuse can also cause it.

None of the above. In two-thirds of all children who have intellectual disability, the cause is unknown.

Causes of intellectual disability

Red Flags

    • Rolling over, sitting up, crawling, or walking late

    • Talking late or having trouble with talking

    • Slow to master things like potty training, dressing, and feeding themselves

    • Difficulty remembering things

    • Inability to connect actions with consequences

    • Behaviour problems such as explosive tantrums

    • Difficulty with problem-solving or logical thinking

In children with severe or profound intellectual disability, there can be other health problems as well. These problems may include seizures, mood disorders, motor skills impairment, vision problems, or hearing problems.

Characteristics of Cognitive

Children with ID do not seem to process information in the same manner as mental age matched typically developing peers. This aspect is critical for learning.  The important skills for learning are attention, discrimination, organization, memory and transfer.

Attention – Children with ID find it difficult to allocate attention towards different subjects and stimuli. The more severe the retardation, the more limited the attention.

Discrimination – Children with ID attend to fewer dimensions of a given task. They fail to relate and understand the different cues in identification of an object.  They need the salient and important clues to discriminate an object. For e.g – A child with moderate ID, will find it hard to discriminate between a horse and a donkey but might be able to discriminate between a dog and an elephant.

Organization – Children with ID have difficulty developing organizational skills and strategies. They fail to process and store simple groups of concepts. They find it difficult to associate words which are similar . E.g – Salt + Pepper, Table + chair, flowers + vase etc. This skill of organizing simple similar categories either visually or auditorily is poor.

Memory – Individuals with ID demonstrate poor recall. The more severe the retardation, the poorer the memory skills. Individuals with mild – moderate ID are able to retain information within long term memory but the retrieval is very slow. Short term memory is quite poor. Children with ID have rapid rate of forgetting, especially in the first 10 seconds. Memory can also be affected by the type of information ( visual or auditory).

Transfer – Transfer or generalization is very difficult for individuals with ID. Learning enhances performance but not generalization.

Speech & Language characteristics

Speech and language delays vary from moderate to severe degrees.  Kids with ID ( Intellectual Disability) develop very little speech while some other children especially those with Fragile X Syndrome and even some Down Syndrome children show “Perseveration” which is excessive talking on a topic when it is appropriate or needless repetition.

The language characteristics are described in the table below.

  • Semantics
  • Syntax
  • Comprehension
  • Pragmatics
  • Phonology
Common disorders which cause Intellectual disability
  • Fragile X Syndrome

Fragile X syndrome is a genetic disorder that causes mental disability. Many parents report that children with Fragile X syndrome have a variety of problems. Some of them are social and, behavioral issues, speech and language difficulties, and sensory issues. There is no cure for this disorder. However, therapy services can help children learn important skills. Services can include therapy Speech therapy, Physiotherapy, Occupational therapy, Behavior therapy, etc. Therapists also help you in providing tips to work at home. This article mainly focuses on Speech tips for Fragile X syndrome.

  • Down Syndrome

Children with Down syndrome learn to sit, walk, talk, play and do most other activities, only somewhat later than their peers without Down syndrome.

People with Down syndrome attend school, work and contribute to society in many delightful ways. The children with DS should be provided with quality educational programs, a stimulating home environment, good health care and positive support from family, friends and communities.

  • Autism

Autism is normally the common name for Autism Spectrum Disorder (ASD). ASD is the collective term for individuals affected in the aforementioned areas. Due to the diverse symptoms the word spectrum is used. Another term often heard is Pervasive Developmental Disorder ( PDD). This refers to the milder form of Autism while ASD is the more severe form.

  • Prader Willi Syndrome

Prader- Willi syndrome a genetic condition caused by the loss of gene function on chromosome 15.Chromosome 15 has small molecules called nucleolar (snoRNAs). These have a variety of functions including regulation of other types of RNA molecules. Studies suggest that loss of a particular group of snoRNA genes, known as SNORD116 cluster, may cause some signs and symptoms of PWS. There is another gene called OCA2 on chromosome 15, loss of which is researched to cause some symptoms of PWS.

  • Carpenter Syndrome

Carpenter syndrome is characterized by premature fusion of some cranial bones (craniosynostosis), abnormalities of fingers and toes, and other developmental delays and deficiencies. Anomalies of fingers and toes includes- Intellectual disability, which ranges from mild to profound.

Treatment & Management

This is a lifelong condition.

Although there is currently no cure, most people can learn to improve their functioning over time. Receiving early, ongoing interventions are beneficial.