What is intellectual disability?

The following overlapping terms are all used when talking about intellectual disability:

  • Intellectual disability

  • Learning disability

  • Learning difficulty

  • Cognitive disability

  • Mental retardation

  • Developmental disabilities

Who uses which term?

  • Most UK social/health services use the term learning disabilities and are likely to continue doing so.

  • UK Government guidance in most areas also uses learning disabilities interchangeably with learning difficulties.

  • In practically every other country learning disabilities is used to describe scholastic disabilities, such as those often characterised as dyslexia.

  • The World Health Organisation (WHO) recommend the term intellectual disabilities.

  • The WHO (along with the United Nations (UN)) also use the term mental retardation, but this has negative connotations in the UK.

  • It's important to be aware that most non-UK references to learning disabilities are not referring to intellectual disabilities.

What is intellectual disability?

Considering affected people


The UK Government Paper Valuing People (2001) quotes 1999 figures for incidence of learning/intellectual disabilities as

  • mild intellectual disabilities: 25 per 1000 people or 1.2 million people in total

  • severe and profound intellectual disabilities: 210,000 people.

The Mencap website (2008) quotes 2007 figures as

  • 1.5 million people in the UK have an intellectual disability

  • 200 babies are born with a learning disability every week

The number of people with intellectual disabilities is rising by about 1% a year because of

  • better life-expectancy, for example for people with Down's Syndrome

  • better life-expectancy and post-natal care

  • the increasing number of children surviving birth complications