Healthy carriers of a gene that increases the risk of depression have altered activity in brain circuits involved in emotion, reports a brain imaging study in the June issue of Nature Neuroscience. The findings may help to explain how genetic makeup can lead to increased susceptibility to depression.
An increased risk for depression has been linked to one variant of a gene that controls levels of the brain chemical serotonin, thought to be involved in mood regulation. People that carry this variant are more likely to develop depression, particularly if exposed to stressful or traumatic life experiences. Daniel Weinberger and colleagues imaged the brains of over one hundred healthy individuals with no prior history of depression. Carriers of the high-risk gene variant had reduced brain volume and altered interactions between regions of brain circuit that may be important for controlling negative emotional responses.
Previous imaging studies have found changes in the brains of depressed patients, but it was not clear whether these changes were caused by depression or whether they might be present before its onset. The new results suggest that genes shape brain structure and function, which in turn may contribute to individual variation in temperament and vulnerability to mood disorders.
Daniel R. Weinberger (National Institute of Mental Health, NIH, Bethesda, MD, USA)
Additional contact for comment on paper:
Stephan Hamann (Emory University, Atlanta, GA, USA)
Online publication can be accessed by clicking here.
(C) Nature Neuroscience press release.
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