____________________ of the DSM-IV is used to classify personality disorders and mental retardation.

DSM-IV

The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, a handbook used by healthcare professionals in diagnosing mental disorders.

Personality Disorders

A group of mental disorders characterized by long-term unhealthy patterns of thought and behavior, significantly impairing social functioning.

Mental Retardation

An outdated and now considered offensive term for intellectual disability, which is characterized by significant limitations in intellectual functioning and adaptive behavior.