Syafrita et al. [17] studied 72 post-ischemic stroke patients and found that serum BDNF levels in the acute phase of stroke were significantly lower in PSD patients as compared to non-PSD patients (p = .009), with serum BDNF levels significantly negatively correlated with the risk of PSD development (r = - .308) [17]. The gene discussed is BDNF; the disease is stroke disorder.