CAUSES OF MENTAL ILLNESS:
Several factors have been linked to the development of mental illness. In many cases, there is no single or consistent cause established, but rather, a combination of factors that contribute to the disorder. There is a common view held among professionals that mental illness disorders often result from genetic vulnerabilities combining with environmental stressors. Stressful events surrounding pregnancy have also been implicated in a cause of mental illness, and traumatic brain injury may also increase the risk of developing certain mental disorders. There are also some inconsistent links found between certain viral infections and mental illness, as well as substance abuse and to general physical health. Other possible causes of mental illness include abnormal functioning of neurotransmitter systems, including serotonin, norepinephrine, dopamine and glutamate systems. Differences have been found in the size or activity of certain brain regions in some cases, and psychological mechanisms have also been implicated, such as cognitive and emotional processes, personality, temperament and coping styles.
Certain social influences have also been found to be an important factor in contributing to mental illness. These include any kind of abuse, bullying and other negative life experiences. Specifics as to how these life stressors affect a person is not clear, however. Other risks implicated include employment problems, socioeconomic inequality, problems linked to migration and certain features of particular societies and cultures.
CAUSES OF MENTAL RETARDATION:
In approximately two-thirds of mental retardation cases, the cause is one of four factors: heredity, prenatal problems, childhood illness or environmental factors. In the remaining one-third of all cases, the cause is unknown.
Approximately five percent of mental retardation cases are caused by genetic factors. This results from abnormality of genes inherited from parents or errors when genes combine. These abnormal genes may interfere with the normal development of the child’s brain, which leads to mental retardation. Abnormal genes may also be the result of infections during pregnancy, infections, overexposure to x-rays and other factors. Inborn errors of metabolism which may produce mental retardation, such as PKU (phenylketonuria), also fall into this category. Chromosomal abnormalities have also been related to some forms of mental retardation, such as Down syndrome and fragile X syndrome.
Mental retardation can be caused by any condition which impairs the development of the brain during pregnancy or during birth. In about one-third of the cases, the cause remains unknown, however. Use of alcohol or drugs by the pregnant mother is one of the major causes of mental retardation. Other risks are malnutrition, rubella, glanular disorders and diabetes, cytomegalovirus, and many other illnesses of the mother during pregnancy.
Any birth condition of unusual stress may injure the infant’s brain, premature birth and low birth weight also predict serious problems more often than any other conditions.
Childhood diseases linked to mental retardation include whooping cough, chicken pox, measles, and Hib disease which may lead to meningitis and encephalitis which can damage the brain. Accidents such as a blow to the head or near drowning and substances such as lead and mercury can also cause irreparable damage to the brain and nervous system.
Environmental factors that may result in mental retardation include malnutrition, disease-producing conditions, inadequate medical care and environmental health hazards. Also, children in poor areas may be deprived of many common cultural and day- to-day experiences provided to other Children. Research suggests that such “under-stimulation” can result in irreversible damage and can serve as a cause of mental retardation.