Depression's Causal Mechanism Identified

Major depressive disorder is associated with alterations in the activity and connectivity of brain systems which underlie reward and memory, according to the results of a recent study. These results could help to determine which regions of the brain may be associated with symptoms in these patients.

For their study, researchers measured the influence of brain regions on one another in patients with depression using effective connectivity, which allows for a more detailed analysis than in previous brain imaging studies.
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They included 336 patients with major depressive disorder and 350 healthy controls in their study. Overall, they found that the medial orbitofrontal cortex, which is associated with reward and subjective pleasure, has reduced effective connectivity from temporal lobe input areas, the lateral orbitofrontal cortex, associated with nonreward, has increased activity, and the hippocampus, associated with memory, has increased activity in patients with depression.

“These findings are part of a concerted approach to better understand the brain mechanisms related to depression, and thereby to lead to new ways of understanding and treating depression,” the researchers concluded.

—Michael Potts

References:

Rolls ET, Cheng W, Gilson M, et al. Effective connectivity in depression [published online October 23, 2017]. Biol Psychiatry Cogn Neurosci Neuroimaging. https://doi.org/10.1016/j.bpsc.2017.10.004.

Depression’s causal mechanisms identified with new method [press release]. Warwick. https://warwick.ac.uk/newsandevents/pressreleases/depressions_causal_mechanisms_identified_with_new_method1. December 12, 2017.