Updated: Jan 12, 2021

Intellectual disability refers to a disability in the development of a child. This typically manifests in infancy or early childhood years. In a majority of cases, it cannot be diagnosed until the child is older than 5 years. This is because standardized tests used in determining developmental skills become reliable and valid.

Over the years, several terms have been applied to people with intellectual impairment from early life. The word ‘idiot’ was used for people with severe intellectual impairment and ‘imbecile’ for those with moderate impairment. In countries like the USA, learning disability has been generally applied to dyslexia and other specific forms of disability rather than intellectual disability.

It is unsatisfactory to define intellectual disability in terms of intelligence alone. Social criteria which includes the ability of people to lead a normal or near-normal life must be used. This disorder is chronic and often co-occurs with other mental conditions like depression, Attention- Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD).