Itongadol.- A recent study by researchers at Tel Aviv University has confirmed that for many of us, stress is not something we can simply snap out of. About 40 percent of a group of healthy young patients had trouble regaining their composure 20 minutes after a stressful event in a laboratory. This lingering stress was not merely subjective but rather a physiological response clearly visible in fMRI scans and blood tests.
The Tel Aviv team, led by Cognitive Neuroscience professor Talma Hendler and Dr. Noam Shomron of TAU’s Sagol School of Neuroscience and Sackler School of Medicine, says that the study’s findings can be used to develop a blood test measuring how well a patient regulates stress. If the blood test discovers that a person regulates stress poorly, the researchers expect to develop methods to train them to “just relax” at will.
Tel Aviv University doctoral student Sharon Vaisvaser explained the setup to The Times of Israel.
“We recruited 49 (male) combat soldiers at the beginning of their service, before being exposed to any dangerous situations, so they don’t have PTSD. I asked them to do math problems in their head and I pressured them. I said, ‘Hurry up, Why don’t you concentrate? You can do better, you’re not performing as well as the others.’”
The test was a variation of the Trier Social Stress Test, used by psychologists to reliably produce stress in lab subjects. Vaisvaser says that all the young men had a stress response, as measured by their heart rate, cortisol levels and brain activity as well as by an fMRI machine and changes in a micro-RNA known as 29c in their blood.
When asked how they felt immediately following the test, all the subjects reported stress. But 20 minutes later, 40 percent of the subjects reported that they continued to feel stressed. Brain scans as well as micro-RNA 29c levels corroborated what they said.
Do we always know when we’re stressed?
Shomron says that there is a strong correlation between the level of stress a person reports and the physiological indicators in their brain and blood. Nevertheless, what we say, or even believe, we feel is not an accurate reflection of what is going on in our body.
“A combat soldier will not admit to feeling anxious,” says Shomron. Conversely, a person may repeat “I’m so stressed, I’m so stressed ” as a way of calming themselves down or winning sympathy.
That’s why the Tel Aviv researchers set out to establish objective markers of poor stress regulation. What they found was that a specific alteration in the expression of the microRNA miR-29c was greater among the stress sustainers, the 40% of subjects who had a slow recovery from stress, than the 60% who recovered quickly. This change corresponded with modified connectivity of an area of the brain associated with stress regulation, the vento-medial prefrontal cortex (vmPFC).
Does that mean that susceptibility to prolonged stress is a fixed, possibly genetic predisposition?
Not necessarily, says Shomron. “It’s epigenetic,” meaning that certain genes get turned on or off depending on your experiences and environment.
Vaisvaser speculates as to how this might work in childhood. Children are born with different temperaments but both a childhood that was too stressful and one that was not stressful enough can cause genes to be expressed that might weaken a person’s stress regulation. Neglectful or abusive parents are bad for the child, but so are “helicopter parents” who cater to their offspring’s every whim.
“There’s this concept of the ‘good enough parent,’ that a child’s environment has to be good enough but not perfect,” says Vaisvaser. “We need to be obstructed and frustrated so we can learn to separate between who we are and someone else.”
Stress does build up your resilience to further stress, she adds, but only if it’s a level of suffering you can handle.
In her recent book, “Cure: A Journey Into the Science of Mind Over Body,” science journalist Jo Marchant makes a similar point:
Let’s say a skier is about to go down a snowy mountain. If he is experienced and confident in his ability to make it down safely, he will experience exhilaration, which is one version of the stress response. It causes peripheral blood vessels to dilate and the heart to pump blood more efficiently, boosting physical and mental performance. On the other hand, if the skier feels fear, the body will go into damage control mode, with the heart beating less efficiently so as to minimize blood loss in the event of injury. The stress hormone cortisol will surge to prepare the immune system for infection or injury. Psychologists call these two types of responses to stress “challenge” and “threat.”
Marchant says that the challenge response is largely beneficial for our long-term health, as long as we have time to rest in between challenges. But the threat response, repeated over time, causes us to develop poor stress regulation, which can lead to such conditions as heart disease, chronic inflammation and even PTSD.
Marchant compares the body’s stress response to exercise:
“Just as with physical exercise, if we put our bodies under a manageable amount of stress, then go home and rest, this eventually makes us stronger and more resilient. In essence this is what we’re doing every time we go on a roller coaster or watch a scary film.”
Noam Shomron says he hopes a drug company or diagnostic company develops a blood test using the results of the TAU study, although it could take several years to receive FDA approval. He imagines people taking the test before deciding to go into a high-stress job, like firefighter or kindergarten teacher.
But won’t such a test label people as “poor stress regulators” and prevent them from pushing themselves or trying new things?
“The idea is not to label people,” says Vaisvaser, “just to help them. We definitely believe in plasticity, that the brain changes over time.”
“You can train your brain to come out of stress,” says Shomron, “Talma’s lab can map your brain with an fMRI and you can view it while it’s being mapped. You will get a reward if your brain activates a particular region, and if your body gets a reward you can change — just like you get a reward for moving your hands when you are a baby.”
The researchers are planning a second study on emotional regulation and teaching people strategies to calm themselves, for instance, using cognitive reappraisal techniques while watching the results on an fMRI. Since fMRIs are large and expensive the team eventually hopes to learn how to train people using an EEG headset that measures brain waves, which can be bought for a few hundred dollars.
“This wouldn’t replace psychotherapy,” explains Vaisvaser. “Our goal is to make medicine more personalized. I am a movement therapist by profession and if there’s one thing I learned from this study it’s that the mind and body are integrated, that we’re the entire package.”