BDNF and major depressive disorder: In the individual group analyses, the PDM group exhibited a significant main effect of menstrual cycle on state anxiety (F = 33.144, R2 = 0.309, P<0.001), Beck Anxiety Inventory (F = 85.498, R2 = 0.536, P<0.001), Beck Depression Inventory (F = 45.579, R2 = 0.381, P<0.001), and Pain Catastrophizing Scale (F = 7.556, R2 = 0.095, P = 0.008) scores, as well as a significant interaction between menstrual cycle and BDNF genotype on the Beck Anxiety Inventory score (F = 7.743, R2 = 0.095, P = 0.007) (Table 5).