Depressed see the world in shades of gray

FREIBERG, Germany, July 20 (UPI) -- People suffering from depression actually do find the world a gray place, researchers say, and have trouble detecting black-and-white contrast differences.

Researchers at the University of Freiburg in Germany had 40 subjects with major depression and 40 healthy subjects view a sequence of black-and-white checkerboards of different contrasts while measuring their visual response, LiveScience.com reported Tuesday.

Using a measuring device called an electroretinogram, they found the depressed subject has dramatically lower retinal response than the healthy subjects to the different black-and-white contrasts.

The results stayed the same regardless of whether patients were taking antidepressants, researchers say.

"These data highlight the profound ways that depression alters one's experience of the world," Dr. John Krystal, editor of the journal Biological Psychiatry which published the study, said.

"The poet William Cowper said that 'variety's the very spice of life,' yet when people are depressed, they are less able to perceive contrasts in the visual world," Krystal said. "This loss would seem to make the world a less pleasurable place."