Diseases & National Health Programme
Mental retardation is defined if IQ is below:
Intelligence Quotient (IQ) is an index of relative intelligence determined through the subject's answers to arbitrarily chosen questions. Persons scoring 70 or less are considered mentally retarded.
The WHO has given the following classification of mental retardation:
a. Mild mental retardation 50-70
b. Moderate mental retardation 35-49
c. Severe mental retardation 20-34
d. Profound mental retardation < 20