Intricate role of sleep deprivation in modulating depression: focusing on BDNF, VEGF, serotonin, cortisol, and TNF-α

In this review article, we aimed to discuss intricate roles of SD in modulating depression in preclinical and clinical studies. Decades of research have shown the inconsistent effects of SD on depression, focusing on SD duration. However, inconsistent role of SD seems to be more complicated, and SD duration cannot be the only one factor. Regarding this issue, we chose some important factors involved in the effects of SD on cognitive functions and mood including brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), serotonin, cortisol, and tumor necrosis factor-alpha (TNF-alpha). It was concluded that SD has a wide-range of inconsistent effects on BDNF, VEGF, serotonin, and cortisol levels. It was noted that BDNF diurnal rhythm is significantly involved in the modulatory role of SD in depression. Furthermore, the important role of VEGF in blood-brain barrier permeability which is involved in modulating depression was discussed. It was also noted that there is a negative correlation between cortisol and BDNF that modulates depression. Eventually, it was concluded that TNF-alpha regulates sleep/wake cycle and is involved in the vulnerability to cognitive and behavioral impairments following SD. TNF-alpha also increases the permeability of the blood-brain barrier which is accompanied by depressive behavior. In sum, it was suggested that future studies should focus on these mechanisms/factors to better investigate the reasons behind intricate roles of SD in modulating depression.

Automated summary

This review article discusses the intricate roles of sleep deprivation (SD) in modulating depression. The inconsistent effects of SD on depression have been studied for decades, with a focus on SD duration. However, the inconsistent role of SD seems to be more complicated, and other factors such as brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), serotonin, cortisol, and tumor necrosis factor-alpha (TNF-alpha) are involved. It was concluded that SD has inconsistent effects on BDNF, VEGF, serotonin, and cortisol levels. The diurnal rhythm of BDNF is significant in the modulatory role of SD in depression. VEGF is important in blood-brain barrier permeability which affects depression. Furthermore, there is a negative correlation between cortisol and BDNF, modulating depression. TNF-alpha regulates sleep/wake cycle and increases blood-brain barrier permeability, resulting in depressive behavior. Future studies should focus on these mechanisms/factors to better understand the complex roles of SD in modulating depression.