Mentally Retarded Definition:

Significantly subaverage intellectual functioning.

Mental retardation is a mental disorder which is usually congenital, usually observed and diagnosed from birth or in childhood.

The American Psychiatric Association, in their DSM-IV Manual defines mental retardation as follows:

"Significantly subaverage intellectual functiong - an IQ of approximately 70 or below - with onset before the age of 18 years and concurrent deficits or impairments in adaptive functioning."

According to the DSM-IV catalogue of mental disorders, mental retardation can be:

• Mild;
• Moderate;
• Severe; or
• Profound.

But other publications¹ suggest five classes of severity: borderline (an IQ of 68-83), mild, moderate, severe and profound, whereas some general medicine publications suggest eight scales of severity.

Mental retardation is distuiguished, as a mental disorder, from learning, attention deficit or anxiety disorders.

REFERENCES:

• American Psychiatric Association, Diagnostic and Stastical Manual of Mental Disorders, 4th ed. (Washington, DC: American Psychiatric Association, 2000)
• Duhaime, Lloyd, Duhaime's Legal Dictionary
• Duhaime, Lloyd, Duhaime's Legal Citations & Abbreviations
• Schmidt, J.E., Attorney's Dictionary of Medicine, Volume 4 (Newark, New Jersey: LexisNexis, 2009), page M-133 (note 1)
• Woody, R. H., Legal Aspects of Mental Retardation (Springfield, Ill: Charles C. Thomas Publisher, 1974)