Intellectual disability

generalized neurodevelopmental disorder

thumb|The Idiot by Evert Larock (1892)

poisoning by lead in the body, especially affects the brain

human disease

rare multisystem genetic disease that causes benign tumors to grow in the brain and on other vital organs

hypothyroidism that is present at birth

The term imbecile was once used by psychiatrists to denote a category of people with moderate to severe intellectual disability, as well as a type of criminal. The word arises from the Latin word imbecillus, meaning weak, or weak-minded. It originally referred to people of the second order in a former and discarded classification of intellectual disability, with a mental age of three to seven years and an IQ of 25–50, above "idiot" (IQ below 25) and below "moron" (IQ of 51–70). In the obsolete medical classification (ICD-9, 1977), these people were said to have "moderate mental retardation" or

term once used in psychiatry to denote mild intellectual disability

age relative to intellectual performance

unethical human experiments in Sweden, 1945–55

The term feeble-minded was used from the late 19th century in Europe, the United States, and Australasia for disorders later referred to as illnesses, deficiencies of the mind, and disabilities.

below-average cognitive ability (IQ 70–85) that is not as severe as intellectual disability (<70)

partial or complete triplication of chromosome 22

syndromic intellectual characterized by an X-linked inheritance pattern

medical condition

Human disease

subnormal intellectual functioning (cognitive disorder)