People with depression have a distinguishing feature in their brains: They have fewer astrocytes, a type of star-shaped brain cell, compared with the brains of people without mental health disorders, according to a new study. 

“Astrocytes are hugely affected in depression” in terms of their cell numbers, study co-author Liam O’Leary, a doctoral candidate in the Department of Psychiatry at McGill University in Montreal, told Live Science. “It has been known before now that this happens, but we show here that it happens throughout the brain” rather than in one specific brain region. This “makes us think that this [lower astrocyte quantity] is a much bigger part of depression, one which might be amenable to new treatment strategies,” he said.