About Mental Retardation (from Wikipedia)
Mental retardation is a generalized disorder, characterized by significantly impaired cognitive functioning and deficits in two or more adaptive behaviors with onset before the age of 18. Once focused almost entirely on cognition, the definition now includes both a component relating to mental functioning and one relating to individuals' functional skills in their environment.
Links –
http://en.wikipedia.org/wiki/Mental_retardation
http://www.mrrc.npi.ucla.edu/mrrc/default.html
http://www.cdc.gov/ncbddd/dd/ddmr.htm
http://kidshealth.org/kid/health_problems/birth_defect/mental_retardation.html
http://www.searo.who.int/en/Section1174/Section1199/Section1567/Section1825_8073.htm





