BDNF and Alzheimer disease: In AD, there is an association between the rate of cognitive decline and BDNF serum levels, amyloid beta (Aβ1-42) plasma levels and the degree of platelet activation (activated GP IIb-IIIa and P-selectin) (Laske et al., 2010; Stellos et al., 2010; Laske et al., 2011).