Mental retardation is a genetic disorder mainfested in significantly below average overall intellectual functioning and deficits in adaptive behavior. Mental retardation is a particular state of functioning that begins in childhood and is characterized by decreased intelligence and adaptive skills. Mental retardation is the most common developmental disorder.
The causes of mental retardation can be classified into biomedical, social, behavioral, and educational risk factors. Biomedical factors are related to biological processes, such as genetic disorders or nutrition. Social factors are related to social and family interaction, such as child stimulation and adult responsiveness. Behavioral factors are related to harmful behaviors, such as maternal substance abuse. Educational factors are related to the availability of family and educational supports that promote mental development and increases in adaptive skills.
Some of the most common known causes of mental retardation that occur before birth are Down syndrome, fetal alcohol syndrome, and fragile X syndrome. Other causes that take place before a child is born include genetic conditions, such as Cri-du-chat syndrome or Prader-Willi syndrome, infections, or birth defects that affect the brain. Mental retardation may also occur while a baby is being born or soon after birth, such as asphyxia, or may occur when a child is older. Serious head injury, stroke, or certain infections such as meningitis can cause mental retardation in older children.
Intelligence refers to a general mental capability. It involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly, and learn from experience. Mental retardation is generally thought to be present if an individual has an IQ test score of approximately 70 or below. Adaptive behavior is the collection of conceptual, social, and practical skills that people have learned so they can function in their everyday lives.
State laws defining mental retardation vary by state. A state statute may generally define mental retardation as having a significant difference between the expected level of development for their age and their current level of functioning, based upon a determination made by qualified personnel. Definitions of mental retardation may vary depending on the purpose for which the definition is used. For example, an adoption agency seeking to place a child for adoption may define mental retardation differently from a state agency which provides assistance for the mentally retarded.
Some states have a Department of Mental Retardation (DMR) or provide similar services through a department of human services. Home and Community Based Waiver (HCBS) is a federal program authorized by Section 1915 (c) of the Social Security Act. The HCBS waiver for mental retardation/developmental disability is a Medicaid program that covers home and community based services for individuals eligible for DMR services and meet the Medicaid and HCBS waiver criteria for participation in the waiver.