HU Research Reshapes Future of Psychiatric Medicine & Depression

Groundbreaking research, headed by Prof. Raz Yirmiya of The Hebrew University, advances psychiatry’s understanding and ability to treat depression. Yirmiya was the senior editor of an article, published in the Trends of Neurosciencesjournal,that redirects the field's focus from neurons (responsible for the brain's thinking and control over the body) to the cells in its immune system called the microglia.

Depression, which afflicts one in six people, is the leading global cause of disability – surpassing cardiovascular and respiratory diseases, cancer and HIV/AIDS combined. By expanding the scope of the field's research, Yirmiya's discovery could potentially inspire a new generation of anti-depressant medications for patients who were unresponsive to traditional medications. In his article, Yirmiya claims that he believes medicine geared to allow the microglia to function normally will work also as efficient anti-depressants.

Ten percent of our brain cells consist of the microglia, which function as the brain's "immune system" fighting bacteria and viruses in the brain. The microglia are also responsible for assisting the brain's healing process after it experiences trauma. "Studies in humans, using post-mortem brain tissues or special imaging techniques, as well as studies in animal models of depression, demonstrated that when the structure and function of microglia change, these cells can no longer regulate normal brain and behavior processes and this can lead to depression," said Yirmiya .

The microglia's abilities are often damaged in situations that may cause depression such as aging, trauma, and diseases such as Alzheimer's disease. These conditions "activate" the microglia causing them to swell and secrete compounds that cause neural inflammation. Yirmiya's article sheds light on other possible causes of depression and new routes doctors can choose when treating their patients.