BDNF and depressive disorder: We have previously shown that maternal sleep deprivation increases anxiety, depression, and cognitive dysfunction, which are associated with reductions in the expression of brain-derived neurotrophic factor (BDNF), PSD-95, and SYN in the hippocampus (Wei et al., 2022; Zhang Y. et al., 2022; Zhang Z. et al., 2022; Zhang et al., 2023a,b).