• Mental age range: 5-8 years old
• IQ ranges: 50-70, affects 85 percent of population
• Language: functional with ability to effectively use a communication device
• Self-help: good.
• Social skills: capable of meaningful, yet immature relationships with peers and the opposite sex. Academic skills: can achieve up to sixth-grade level by late teens, although average achievement is at third-grade level.
• Vocational status: generally adequate for minimum self-support; some achieve semi- skilled or helper status; others are capable of unskilled employment on a competitive to marginally competitive basis
• Adult status: most typically marry and become parents; can maintain an independent adjustment but may need assistance during periods of stress

Moderate Mental Retardation Characteristics:

• Mental age range: 1-5 years old
• IQ ranges: 35-50
• Language: functional although intelligibility may be greatly impaired; limited ability to use a communication device
• Self-help: partial to nearly complete
• Social skills: diminished ability to form relationships; may distinguish own needs and wants but disregard the needs of others
• Academic skills: unlikely to progress beyond second-grade level Vocational status: capable of some degree of productive unskilled or semi-skilled labor performed under close supervision, or in sheltered workshops with ability to travel alone in familiar surroundings
• Adult status: seldom marry, but capable of self-management required for independent living' adapts well to life in a community living environment as well as supervised group homes

Severe Mental Retardation Characteristics:

• Mental age range: 2 months 1 year
• IQ ranges: 20-35
• Language: slight communicative speech, often speaking in phrases
• Self-help: partial with assistance
• E. Social skills: capable of forming bonds with peers and adults
• Academic skills: can become familiar with alphabet, counting, leam sight-reading of common survival words O
• Vocational status: can benefit from activity center programs
• Adult status: dependent requiring constant need for supervision; can often live with family or in a community group home in community. Profound

Mental Retardation Characteristics

• IQ ranges: below 20, affects 1-2percent of population
• Mental age: 0-6 months
• Language: no commutative speech, except to say a few words often not appropriate for situation; unable to understand simple phrases n
• Self-help: little to partial assistance C.
• Social skills: often enjoys individualized attention
• Academic skills: none El
• Vocational status: benefits from activity center programs with basic stimulation activities
• 11 Adult status: needs constant supervision; often resides in ICF-DD facility or community group homes Symptoms
• Failure to meet intellectual developmental markers
• Persistence of infantile behavior
• Lack of curiosity
• Decreased leaming ability
• Inability to meet educational demands of school
• Deviations in normal adaptive behaviors depend on the severity of the condition. Mild retardation may be associated with a lack of curiosity and quiet behavior. Severe mental retardation is associated with infantile behavior throughout life.

Causes

Causes of mental retardation are numerous, but a specific reason for mental retardation is determined in only 25 percent of cases.
Failure to adapt normally and grow intellectually may become apparent early in life or, in the case of mild retardation. may not become recognizable until school age or later. An assessment of age-appropriate adaptive behaviors can be ,ade by the use of developmental screening tests. The failure to achieve developmental milestones is suggestive of mental retardation.
A family may suspect mental retardation if motor skills, language skills, and self-help skills do not seem to be developing in a child or are developing far more slowly than among the child's peers. The degree of impairment from mental retardation ranges widely, from profound impairment to mild or borderline retardation. Less emphasis is now placed on degree of retardation and more on the amount of intervention and care required for daily life.
Causes of mental retardation can be roughly broken down into several categories:

• unexplained (the largest category)
• trauma (prenatal and postnatal) such as oxygen deprivation before, during or after birth
• infection (congenital and postnatal)
• Chromosomal abnormalities
• Genetic abnormalities and inherited
• metabolic disorders metabolic disorders
• toxins such as lead or mercury poisoning
• nutritional deficits such as severe malnutrition
• environment