Canadian researchers have discovered that other people’s stress can alter your brain as much as real stress.
The effects of stress are widespread. Psychologically, stress is tied to depression, anxiety disorders, and PTSD. Physically, chronic stress is linked to inflammation that can increased the risk for heart disease, diabetes, musculoskeletal disorders, respiratory problems, chronic pain, and more.
Emotion researchers have long known that feelings like joy, sadness, and anger are “contagious”. This is also true for stress. It can be considerably more difficult to remain calm, focused, and happy when surrounded by others who are angst ridden. But can this contagion also affect our brains? Scientists at the Cumming School of Medicine’s Hotchkiss Brain Institute at the University of Calgary decided to find out.
Brains respond to other's stress
Their study examined the effects of stress on pairs of male and female mice. One mouse from each pair was removed and exposed to a mild stressor and returned to its partner. The team then examined each mouse’s CRH neurons; brain cells that control how the brain responds to stress. Remarkably, the brain cells in both members of the pair responded identically, suggesting that stress was indeed contagious at a neural level.
To better understand why this occurred, the same researchers used an optogenetic method to turn these CRH neurons on and off with light. When they were turned off in the partner mouse when its stressed partner returned to the cage, the stress didn’t “transfer” to the partner mouse. When they turned the CRH neurons in one mouse back on using light, both mice showed changes to their brains as if they’d just encountered a stressful event even when no stressor was present.
Further investigation revealed that the CRH neurons, when activated, released a chemical signal, or pheromone, that alerted other mice to danger. These stress signals are an adaptive means of spreading the word to be on the lookout for threat. They also may represent an important mechanism through which mammals transmit information that can be critical to survival.
This may explain why we feel as though stressful emotions are contagious even when we’re not entirely sure where they’re coming from. It also suggests that others may pick up our stress even when we think we’re hiding it.
How to break the stress contagion cycle
The good news is, we don’t have to be unwitting stress transmitters, or passive recipients of other’s stress. Mindfulness practices like meditation and yoga teach us to become aware of our thoughts, feelings, and behaviors. They can also empower us to directly acknowledge and address our stressful experiences, and to recognize and accept other’s actions and emotions as well.
One of the easiest ways to identify whether or not you’re experiencing stress is to observe the quality of your breath. If you find it to be shallow, rapid, or concentrated in your upper chest, there's a good chance that your nervous system and brain are responding to your experience of stress. You may also be projecting stress to others.
Try modifying your breathing by inhaling deeply, and exhaling as slowly and comfortably as you are able. With time and a bit of practice you can interrupt the stress cycle, and bring a bit more relaxation and present-moment awareness to your day.
Toni-Lee Sterley, Dinara Baimoukhametova, Tamás Füzesi, Agnieszka A. Zurek, Nuria Daviu, Neilen P. Rasiah, David Rosenegger, Jaideep S. Bains. Social transmission and buffering of synaptic changes after stress. Nature Neuroscience, 2018; DOI: 10.1038/s41593-017-0044-6