A study by scientists at EPFL in Lausanne Switzerland shows social status is a major risk factor for developing chronic stress.
In addition, the team discovered a certain kind of identifiable brain activity associated with high risk, something which might make it possible to identify those at risk.
Stress is one factor often associated with mental disorders, however stress doesn’t affect everyone in the same way. Long term adversity brings on depression is some, while others prove more resilient and adaptable.
The Carmen Sandi laboratory at EPFL, which has been researching stress for many years, studied the effects of social status on stress levels in mice.
Mice of different social status were subjected to adversity and then monitored.
The first step was to identify the socially dominant ones. This was done by introducing competitive tasks. Then researchers exposed all of the mice to adversity.
Those identified as dominant were more likely to suffer from stress-induced depression than the subordinate mice. The depressed mice became socially withdrawn.
MRI scans of the mice revealed big differences in activity levels in a part of the brain known as the accumbens nucleus. Before adversity this part of the brain was more active in dominent mice. However, after being exposed to adversity brain responses were very different. Accumbens nucleus activity in the subordinate mice rose, but remained unchanged in the dominant mice.
“Our discovery reinforces the idea that losing social status is a greater factor in developing depression that low social status” said Carmen Sandi.
This is the first non-invasive study to find a connection between, brain activity, social status and stress. It could be used in the future to identify people at risk and could have wide ranging implications given the prevalence of hierarchical structures in human society.