Besides, as a member of the metzincin family of extracellularly operating proteases, MMP-9 has been found to participates in brain physiology and pathology and contributes to a large variety of brain disorders, including epilepsy, schizophrenia, stroke, neurodegeneration, depression, brain tumors, etc. Therefore, the relationship between antidepressant effect of EDC and MMP-9 regulation will be further studied in the future. Here, MMP9 is linked to major depressive disorder.