Mental Retardation

Impaired or incomplete mental development characterized by an IQ of 70 or below and characterized by significant functional limitations in at least two of the following skills: communication, self-care, home living, social/interpersonal skills, use of community resources, self-direction, functional academic skills, work, leisure, health, and safety. Onset usually occurs before age 18. More than 200 specific causes of mental retardation have been identified. Degrees of severity reflect the level of intellectual impairment:

• Mild Mental Retardation - IQ level 50-55 to approximately 70
• Moderate Retardation - IQ level 35-40 to 50-55
• Severe Mental Retardation - IQ level 20-25 to 35-40
• Profound Mental Retardation - IQ level below 20-25

Source: Children Welfare Information Gateway

Last reviewed October 2023