0
Mental retardation may be caused by an inherited abnormality of the genes, such as fragile X syndrome.
No, it isn't. In fact, for sufferers of bipolar II especially, it has been linked to increased creativity and functionality.
Fragile X, a defect in the chromosome that determines sex, is the most common inherited cause of mental retardation.
Overstudy does not cause mental retardation.
Drug abuse and cigarette smoking during pregnancy have also been linked to mental retardation.