BDNF and Behcet disease: Only Barbosa et al. (2010) [51] and Poletti et al. (2017) [52] showed higher BDNF circulating levels in BD patients during acute episodes, while Binici et al. (2016) [53], Ameele et al. (2017) [54], and Skibinska et al. (2021) [55] observed no significant difference in BDNF circulating levels between acute episodes of BD patients and HC.