From this recent paper, Sept 2014, n=237http://journal.frontiersin.org/article/ ... 00236/full
This is an interesting conclusion in regards to BDNF, (rs6265)
"Third, the other polymorphism (BDNF) was not statisti- cally associated with the targeted outcomes. In general, BDNF- cognition associations are inconsistently observed and difficult to interpret (Mandelman and Grigorenko, 2012). In addition, BDNF associations are rarely tested as predictors of clinical or cognitive status or neurodegenerative changes (cf. Forlenza et al., 2010). The mechanisms through which BDNF may affect neurocogni- tive performance are proposed (Savitz et al., 2006; Harris and Deary, 2011) but their relevance to non-normal cognitive status has not been firmly established. As an MCI predictor, BDNF may be less relevant for early classification (as in this study) than for later cognitive impairment (Forlenza et al., 2010). We included BDNF for two reasons: (a) it could have been related to objective cognitive status as we assess it (via performance on a reference battery including memory and speed markers) and (b) it could have appeared as an associate of cognitive status in the role of interacting influence."