Decreased Perception of Color in Depression
Is it true that the world looks gray when you are depressed?
Science may back up the sense that colors just don’t seem as bright during a major depression.
Recent research published by Dr. Emanuel Bubl of the Department of Psychiatry and Psychotherapy at Albert-Ludwigs-University of Frieburg in Germany, and his colleagues, showed that the retinas of depressed patients were less sensitive to contrast.
Art, literature, and popular culture, today, and throughout history, make reference to depression as “blackness” or “gray,” or tell people who are sad to “brighten up.” Previous research has demonstrated that depressed patients themselves perceive that their vision is not as acute as when they were not depressed, and that they see less visual contrast.
Bubl and his team used a technique called a pattern electroretinogram (PERG) to objectively measure the participant’s ability to perceive contrast. A PERG is a device which measures the tiny amount of electrical change in the eye made when the retina is stimulated by looking at an object with contrast, like a checkerboard. It produces a tracing, much like the heart muscle makes an ECG tracing.
In the current study, 80 patients were enrolled: 20 patients with untreated depression, 20 patients with depression on medication, and 40 patients with no mental health issues. All patients had visual PERGs done.
Bubl found a strong and significant association between the severity of the depression and a decreased response in the PERG, suggesting that the more depressed the patient was, the less their retinas responded to the contrast pattern.
Bubl’s findings are intriguing in that they suggest a scientific basis to a cultural association between depression and a lack of color.
More importantly, however, these finding have potential clinical implications. The diagnosis of depression is based on a constellation of symptoms, both psychological and physical. Most of the psychological symptoms are subjective, and many of the physical symptoms are non-specific, such as weight changes, or sleep changes.
Alterations in PERG response could potentially be an independent, objective, confirmatory, and possibly even specific, diagnostic criterion for depression. An objective criterion for depression would be highly useful for researchers, patients, clinicians, and others.
Speculation as to why the PERG response is diminished in depressed patients might lead to further interesting research into the causes of depression and possibly into novel therapies.
According to Bubl, “Because PERG recording does not depend on subjective ratings, this marker may be an objective correlate of depression in human beings. If replicated, PERG may be helpful in further animal and human research in depression.”
Bubl’s research is published in the July 15th edition of the journal Biological Psychiatry.
Source: Biological Psychiatry
Jones, J. (2014). Decreased Perception of Color in Depression. Psych Central. Retrieved on April 26, 2015, from http://psychcentral.com/news/2010/07/21/decreased-perception-of-color-in-depression/15826.html