Causes Of Mental Retardation And Prevention Efforts

The etiology of mental retardation is variable and complex. In fact, there are more than 350 known disorders and conditions, both genetic and acquired, that can result in mental retardation at different developmental stages. To understand the etiology of mental retardation, it is helpful to consider biological and environmental events that may occur prenatally, perinatally, or postnatally.

Before we examine specific causative agents, it is important to note that in general the estimates of the etiology vary based on the level of severity. Mild retardation is most commonly of idiopathic origins, whereas severe mental retardation most often results from prenatal or genetic factors such as chromosomal abnormalities. For example, for persons with mild retardation, approximately 45-60% of these cases are due to unknown reasons; approximately 10-25% are due to some prenatal, nonchromosomal cause; 4-8% are due to a chromosomal disorder; and 20% of cases can be traced to a perinatal or postnatal cause. When we consider severe mental retardation, as many as 4070% of cases are due to chromosomal disorders or other prenatal factors. Less than 20% of cases are due to perinatal (e.g., prolonged birth anoxia) or postnatal factors, whereas 25-40% of etiologies are unknown.

Anxiety and Depression 101

Anxiety and Depression 101

Everything you ever wanted to know about. We have been discussing depression and anxiety and how different information that is out on the market only seems to target one particular cure for these two common conditions that seem to walk hand in hand.

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