Researchers at the Hebrew University of Jerusalem recently said that some forms of depression may result from malfunctioning brain cells, termed "microglia."
In a theoretical review paper published in the journal Trends in Neurosciences, the researchers said diseased microglia can cause depression, and drugs that can restore the normal functioning of these cells can be effective as fast-acting anti-depressants.
Microglia, the brain's immune cells, comprise 10 percent of all brain cells. They protect against infectious bacteria and viruses in the brain as well as promote the repair and healing processes of damage caused by brain injury and trauma.
"Our views on microglia have dramatically changed over the last decade," Raz Yirmiya, director of the Hebrew University's Laboratory for PsychoNeuroImmunology and senior author of the journal's paper, said."We now know that these cells play a role in the formation and fine-tuning of the connections between neurons (synapses) during brain development, as well as in changes of these connections throughout life."
Studies have shown that when the structure and function of microglia change, the cells can no longer regulate normal brain and behavior processes, which can lead to depression.
Based on this, Yirmiya and his fellow researchers said that the same class of drugs currently being used to treat depression cannot treat the disease uniformly. Instead, they said a personalized medical approach should be adopted in which the status of the microglia in the individual patient should be established first.
