Here we observed negative associations between serum BDNF and NDEV Aβ42 and P-T181-tau in AD samples of both the NDEV Study and the RCT (Aβ42: r = –0.207, p = 0.034; P-T181-tau: r = –0.218, p = 0.024), suggesting that an interaction between increases in serum BDNF and reductions in NDEV Aβ42 and P-T181-tau might exist and has to be further investigated. Here, BDNF is linked to Alzheimer disease.