subnormal intellectual functioning which originates during the developmental period; multiple potential etiologies, including genetic defects and perinatal insults; intelligence quotient (IQ) scores are commonly used to determine whether an individual is mentally retarded; IQ scores between 70 and 79 are in the borderline mentally retarded range and scores below 67 are in the retarded range.
Impaired intellectual (IQ below 70) and adaptive functioning manifested during the developmental period. Use a more specific term if possible. Use for both the concept of the disorder itself and for populations of mentally retarded persons.
2008 ICD-9-CM Diagnosis Code 319
319Brain - see also condition