In this column, we examine the mental health issues in the context


Recent Discoveries Shed more Light on Mental Retardation in Children

Research on mental retardation or as it is formally known intellectual disability has mushroomed over the past decade. In the year 2011 alone several new discoveries has led the fight against the disorder. For example, Australian Scientists report that two forms of protein seem to contribute to intellectual disability in some subjects. Meanwhile, Researchers at Swedish Medical Karolinska Institutet have discovered new inherited disorder that can cause intellectual disability. At the same time advances are being made in regards of developing treatments that can help treat this condition.
  Mental retardation involves deficits or impairments in intellectual capacity and adaptive skills. The criteria for mental retardation require an IQ level of 70 or below. Plus, deficits or impairments in present adaptive functioning as evidenced by inability to meet standards expected for their age or by their cultural group in at least two areas of adaptive functioning.  These areas include communication, self-care, home living, use of community resources, self-direction, functional academic skills, work, leisure, safety, and social and interpersonal interactions.  In recent years, National Institute of Mental Health has recommended replacing the expression mental retardation with the preferred term “Intellectual disabilities,” however, this term has not yet been fully embraced by the researchers and the academic community. 
 The rate of intellectual disabilities or mental retardation (MR) among general population in this country is estimated at about 2 to 3 percent.  Although, most cases of mental retardation are evident during the first few years of the child’s life, some may not manifest itself till late adolescence.  All cases of MR, however, develop prior to the age of 18. 
 There are five categories of mental retardation.
1-Mild mental retardation: IQ level between 50 to 70.
2- Moderate mental retardation: IQ between 35 to 50. 
3- Severe mental retardation: IQ between 20 to 35. 
4- Profound mental retardation: IQ below 20. 
 5- Unspecified This category is reserved for those cases that the diagnosis of mental retardation is made, but due to severe intellectual impairment or lack of cooperation, standard intelligence testing cannot be administered. Thus, mental retardation is noted but the severity is unspecified.
 In most cases of MR the individual is only mildly retarded.  Unlike the ones with more severe condition, these individuals mostly have normal physical appearance and with appropriate support they can usually live successfully, either independently or in supervised settings in the community.  Their degree of successful functioning, however, depends on many factors including family or social support and the presence or lack of other associated disorders.  In fact, some conditions such as the Dawn’s syndrome or autism are often accompanied with mental retardation.  Naturally, when the child suffers two or more disorders at the same time, it makes it more difficult for him/her to function effectively.
 Causes of mental retardation are multiple.  About 5% are caused by heredity. Approximately 30% of cases are related to early alterations of embryonic development. Pregnancy. The peri-natal (after birth) problems account for roughly 10% of the cases.  In both these instances gene abnormalities can be the cause of mental retardation. Examples include inborn error of metabolism such as PKU- a recessive hereditary disease, as well as the Dawn’s syndrome.
 General medical conditions acquired during infancy or childhood is responsible for about 5% of incidents of mental retardation.  Examples of these medical factors are infections, head traumas, and poisoning conditions such as lead poisoning.
 Also, about 20% of cases of mental retardation are caused by environmental factors. These include deprivation of a nurturing and supportive environment, lack of social or linguistic interactions, non-stimulating environment and severe mental disorders such as autism. Studies also show that severe childhood traumas in stressful environment can cause brain abnormalities leading to mental retardation.
 Research shows that the determination of specific cause of the mental retardation can only be made in 25-50 percent of the cases.  The estimate varies due to uncertainties that still exist even after certain causes are established. For example, the cause may be traced to birth complication or genetic abnormalities, but the exact nature of the problem or the specific gene involved may not be known.
 Any condition that impairs the development of the brain before, during, or after birth and in childhood, can cause mental retardation. According to the research by the American Association on Mental Retardation, when brain injury is the cause of the retardation, 61% of such injuries are made prenatal (before birth).  However, in about 20% of the cases the time of the injury cannot be determined.
 Frequently, children with mental retardation are not diagnosed correctly or remain undiagnosed.  Thus, they are deprived of appropriate care and support. In order to make a diagnosis of mental retardation psychological and adaptive behavior tests should be administered by a properly trained psychologist. According to the American Psychiatric Association’s Diagnostic And Statistical Manual Of Mental Disorders-4th edition, there are no laboratory findings that can uniquely identify mental retardation. However, once the diagnosis of mental retardation is made some diagnostic laboratory findings may help to confirm or to rule out specific accompanying general medical conditions such as chromosomal and genetic defects or central nervous system imaging abnormalities.
 As the research advances, more and more preventive strategies become available to the families and caretakers. The following is a list of preventive measures that can help identify some of the causative factors involved in mental retardation.  By early diagnosis, plus, identifying and remedying these factors parents may be able to protect their children and minimize their risk of developing mental retardation.
 One of the most common intra-uterine causes of mental retardation is ” Fetal alcohol syndrome” and other drug related abnormalities.  These are usually caused by parents who abuse alcohol or drugs.  Obviously, staying sober and following a healthy diet during pregnancy is a good idea for having healthier children.  
 Testing babies at birth for hypothyroidism and phenylketonuria (PKU) can essentially eliminate these causes of mental retardation.  That means, once diagnosed, the above conditions can be remedied by treatments such as thyroid hormone replacement therapy or medication and dietary regimen.
 Severe jaundice and Rh disease in newborn infants also, can cause mental retardation. Timely medication treatment can help treat these conditions in newborns. Also, measles encephalitis and rubella, two other possible precursors of mental retardation, can be treated by measles and rubella vaccines.   In conclusion, early comprehensive prenatal care and preventive measures during and after pregnancy increase the likelihood of preventing mental retardation in children.