Will short-term stress help treat depression and PTSD?
It probably comes as no surprise to anyone that stressful situations, if repeated often or are very intense, can lead to the development of disorders such as depression or post-traumatic disorder. It turns out, however, that stress can also be one of the ways to treat such mental problems.
During the stress response, the so-called HPA axis (hypothalamic-pituitary-adrenal system) is activated, which leads to the secretion of glucocorticoids (e.g. cortisol). The role of these hormones is to stimulate metabolism, improve alertness, memory and other cognitive functions. Although they play an important and useful role during the stress response, too much of them can result in the development of mental disorders.
Chronic stress causes neural and genetic changes in many areas of the brain, including in the prefrontal cortex. It reduces the transmission of neurotransmitters and the activity of nerve cells and leads to the atrophy of dendrites in neurons, which results in depressive disorders. It also deregulates the HPA axis. This suggests that glucocorticoids are crucial in the development of stress-induced depression. On the other hand, some studies indicate that glucocorticoids may be effective in treating depression. This has been shown in both animal (mice) and human studies. Dexamethasone (a synthetic glucocorticoid) given in combination with sertraline or fluoxetine for 4 days improved depression symptoms in a study. A single injection of cortisol produced a similar effect.
So it seems that the same hormones can have both depressant and antidepressant effects.
To better explore this issue, South Korean scientists recently conducted an interesting study on mice. The animals were first exposed to stress for 14 days, for 2 hours a day, which led to depressive behavior. They were then stressed for 14 days as well, but only for 5 minutes a day.
It turned out that stress therapy was as effective in reducing depressive symptoms as the antidepressant imipramine. Interestingly, neither 10 minutes a day nor 15 minutes a day had such an effect. Stress therapy conducted for 5 minutes a day, but only for 3 days or 5 days, was also ineffective. This shows how important the right dose of stress is.
In addition to changing behavior in the mice, changes in various biological markers were observed. Stress therapy, incl. corrected stress-induced dysregulation of the HPA axis, activated various areas of the limbic system, responsible for emotions, and repaired altered gene expression in the prelimbic cortex (part of the prefrontal cortex).
Andrew Huberman and David Spiegel from the US are currently conducting research on stress therapy for the treatment of anxiety disorders and trauma in humans.
They recommend patients to perform 5-minute breathing exercises every day for 2 weeks. However, these are not relaxation exercises, but on the contrary – those that cause a state of stress. They rely on hyperventilation. These are deep inhalations and exhalations that should be done 25-30 times, then exhale as much as possible and hold for 25-60 seconds. Then more cycles until 5 minutes have passed.
Breathing this way leads to an adrenaline rush in most people. In people prone to panic attacks, it can trigger an attack, which is why this therapy is not recommended for such people.
Research is still ongoing, and it’s not yet clear what exactly breathing exercises should look like or how long they should last, but scientists are already hoping that the therapy will be helpful in treating PTSD and other anxiety disorders. Perhaps it will be a recommended addition to cognitive-behavioral therapy.
According to Huberman and Spiegel, the key is that the patient deliberately brings himself into a state of stress, rather than being brought on by some external factor. According to them, only when we intentionally induce stress in ourselves can the prefrontal cortex be activated, which plays an important role in reducing anxiety. So it shouldn’t matter how we induce this state in ourselves. It can also be a cold shower or anything else that will get your adrenaline pumping.
I await the results of their research with interest.
- Lee, EH., Park, JY., Kwon, HJ. i inni. Repeated exposure with short-term behavioral stress resolves pre-existing stress-induced depressive-like behavior in mice. Nature Communications 12, 6682 (2021).
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Author: Maja Kochanowska