Additionally, the neurobiological pathways by which inflammatory responses may play a role in the pathogenesis of PMS/PMDD were elucidated, including their interactions with the hypothalamic-pituitary-ovary (HPO) axis, serotonin—kynurenine (5-HT—KYN) system, GABAergic system, brain-derived neurotrophic factor (BDNF), hypothalamic-pituitary-adrena(HPA)axis and. Here, BDNF is linked to premenstrual tension.