Objective To study the effect of regulation of Xiaoyao Kang'ai Jieyu Prescription on hippocampal neuron postsynaptic density protein 95 (PSD95) in mice with breast cancer related depression, and to elucidate its possible mechanism of protect hippocampus. Methods The BCRD mice model was established by axillary injection of 4T1 inflammatory breast cancer cells combined with subcutaneous injection of corticosterone in the back and randomly divided into model group, paclitaxel group, paclitaxel + fluoxetine group, Xiaoyao Kang'ai Jieyu Prescription group, paclitaxel + Xiaoyao Kang'ai Jieyu Prescri...