Peptide accumulation and the hyperphosphorylation oftau protein, induced by prolonged exposure to high corticosterone concentrations,were prevented by administering mifepristone, a glucocorticoid receptor antagonist,which strengthens the causal relationship between glucocorticoids and theneuropathology of AD.62 Treatment withmifepristone prevented APP cleavage by β-secretase, blocked Aβ production and,consequently, reversed cognitive deficits.62 This evidence concerns the gene APP and Alzheimer disease.