Microglia in the pathogenesis of depression, insomnia and their comorbidity

Microglia have been shown to regulate sleep homeostasis and depressive behavior. However, the mechanism of how microglia are involved in the pathogenesis of depression and insomnia is not well understood. Given the complex and interdependent relationship between sleep and depression, it is important and worthy to clarify the role of microglia in this comorbidity. This review summarizes the current understandings of microglia in insomnia and depression, as well as suggesting their shared mechanisms in neuroinflammation, synaptic plasticity and purinergic signaling, which may promote the precise treatment of comorbid insomnia and depression and facilitate early intervention of insomnia to prevent the onset of depression.