PPARGC1A and major depressive disorder: An increasing body of evidence indicates that the main factors affecting mitochondrial biogenesis include transcriptional coactivator peroxisome proliferator‐activated receptor‐γ coactivator 1α (PGC‐1α), nuclear respiratory factor 1 (NRF1), nuclear respiratory factor 2 (NRF2), 5′‐AMP activated protein kinase (AMPK), Sirtuin1 (SIRT1), mitochondrial transcription factor A (TFAM), etc.56, 57The alterations of these above‐mentioned factors may interrupt mitochondrial biogenesis, and then induce mitochondrial dysfunction, eventually leading to depression.41, 53, 57, 58, 73