Inflammation linked to weakened reward circuits in depression

Anhedonia is the inability to feel pleasure..

http://www.eurekalert.org/pub_releases/2015-11/ehs-ilt112015.php

Public Release: 20-Nov-2015
Inflammation linked to weakened reward circuits in depression
Brain imaging shows distinctive aspects of high-inflammation depression
Emory Health Sciences

About one third of people with depression have high levels of inflammation markers in their blood. New research indicates that persistent inflammation affects the brain in ways that are connected with stubborn symptoms of depression, such as anhedonia, the inability to experience pleasure.

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The findings bolster the case that the high-inflammation form of depression is distinct, and are guiding researchers' plans to test treatments tailored for it.

Anhedonia is a core symptom of depression that is particularly difficult to treat, says lead author Jennifer Felger, PhD, assistant professor of psychiatry and behavioral sciences at Emory University School of Medicine and Winship Cancer Institute.

"Some patients taking antidepressants continue to suffer from anhedonia," Felger says. "Our data suggest that by blocking inflammation or its effects on the brain, we may be able to reverse anhedonia and help depressed individuals who fail to respond to antidepressants."

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A previous study of people with difficult-to-treat depression found that those with high inflammation (as measured with CRP), but not other participants in the study, improved in response to the anti-inflammatory antibody infliximab.

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