In Brief: Depression research: An objective view of gloomy outlook
People who are depressed sometimes describe the world as looking drab. The blues have a way of making things seem gray. A team of German researchers think they know why.
Using an instrument that measures electrical activity in the retina, a group at Albert Ludwig University of Freiburg has shown that the retinas of depressed people don't respond as strongly to certain kinds of visual stimuli as the retinas of people who aren't depressed. They believe their findings, published in the March 2010 issue of Biological Psychiatry, provide some fresh insight into the origins of depression and the role of a brain chemical called dopamine. They also see important implications for future depression research. "The main thing is that this could provide us with an objective measure of depression," said Dr. Ludger Tebartz van Elst in an interview with the Health Letter.
As Dr. Tebartz van Elst and his colleagues point out in their paper, plenty of research has hinted at some sort of physiological connection between vision and depression. But one of the difficulties has been sorting out whether depression affects visual processing in the brain — a definite possibility — or whether the effect occurs further "upstream," in the eye.