Good stress, bad stress: eustress and distress

2023-04-26 · 5 min read

By the kava.fyi editorial team · Last updated: 26 April 2023

Does stress always do harm

Stress is an evolutionary survival mechanism: the body's response to a situation judged to be a threat or a challenge, which shifts the hormonal system into rapid-response mode. It is not, in itself, good or bad, as the classic concept of stress already makes clear: what matters is not whether a stressor appears, but how long it lasts and how well the body copes with it.

Three stages according to Hans Selye

It was the Hungarian-Canadian endocrinologist Hans Selye who first described, in the mid-twentieth century, the general adaptation syndrome, GAS for short, dividing the body's response to a stressor into three stages. In the alarm stage, concentration and motor parameters rise as the body mobilises resources for a rapid response. In the resistance stage, the body adapts to the stressor, either bringing the situation under control or starting to succumb to it. The exhaustion stage appears when the challenge proves too great or lasts too long, and it is this stage that is commonly known as burnout. Selye's concept is sometimes criticised today for its simplifications, among other things for treating the stress response as universal and independent of the type of stressor, but it remains one of the most frequently cited models of the stress response and a starting point for further research into the stress axis.

Eustress and distress: two faces of the same response

It was Selye, too, who coined the distinction between eustress, positive stress that mobilises you to act and is usually short-lived, and distress, negative stress that depletes resources and weakens decision-making. A new project at work, physical effort leading towards a satisfying goal, or cheering on a team together are typical examples of eustress: the body produces a similar hormonal surge to that of a threat, but interprets the situation as exciting rather than dangerous. Distress, in turn, shows up as irritability, excessive arousal or, conversely, apathy and withdrawal, accompanied by a sense that the situation exceeds the resources available. Whether a given stressor becomes eustress or distress for you depends largely on your subjective appraisal of the situation, which is why exactly the same stimulus, public speaking, say, will be an exciting challenge for one person and a source of paralysing anxiety for another.

When short-term stress turns chronic

Short-term stress produces typical, relatively fast-fading symptoms: muscle tension, a faster heartbeat, shallower breathing, a dry mouth, dilated pupils, sometimes nausea or temporary digestive upset. A key role is played by the hypothalamic-pituitary-adrenal axis, which drives the release of cortisol and adrenaline, alongside a rise in blood pressure and glucose and a momentary slowdown of digestive processes. Once the stressor disappears and the resistance stage ends successfully, the body returns to homeostasis. The problem starts when the stressor does not go away and the resistance stage brings no relief: that is when the exhaustion stage sets in and stress becomes chronic. The symptoms of chronic stress are usually far harder to reverse than episodic arousal: neck and back pain, sleep disturbance, weakened immunity, irritability and concentration problems can persist for weeks, even once the original stressor has long since gone.

What chronic stress does to the body

Chronically elevated cortisol is linked, among other things, to a worse mood and falling dopamine and serotonin levels, and, over the longer term, to real health risk. A literature review on cortisol as a biomarker of cardiovascular risk finds that chronic activation of the stress axis is associated with raised inflammation, poorer metabolic control and an increased risk of cardiovascular disease, including heart attack and stroke. That is one reason not to dismiss chronic stress lightly, even though single episodes of short-term stress are a normal and healthy part of functioning.

Where kava fits into this picture

Kava has long featured in the ethnobotanical literature as a Pacific adaptogen, a plant said to help the body cope more effectively with stressful situations. Some of the mechanisms proposed already have a degree of support in research: kavalactones, under laboratory conditions, potentiate GABA A receptors, the same system that dampens excessive neuronal firing and is the target of anti-anxiety medicines. In a 1998 study, kava extract also reversibly inhibited the activity of the MAO B enzyme in blood platelets, something sometimes cited as a possible explanation for kava's effect on mood, though this is an in vitro finding rather than proof of a specific clinical effect. Current scientific reviews, in fact, state plainly that the full hierarchy and precise mechanism of action of kavalactones have still not been conclusively established, and among the proposed molecular targets are also sodium and calcium channels and several other receptors, which suggests that kava's calming effect probably comes from several mechanisms acting in parallel rather than one simple switch.

Kava is also said to have a muscle-relaxing effect and, as some studies suggest, to support sleep quality, which we cover in more depth in the piece on kava and sleep. We describe its relationship with cortisol levels in more detail in the article cortisol and kava, and its mechanism of action on GABA receptors in the piece kava and GABA.

What kava will not do

Kava will not remove the stressor, nor will it substitute for the change in life circumstances that led to chronic overload, and its effect on mood, to the extent it occurs at all, is mild and short-lived. Because it acts on the central nervous system and, as laboratory studies show, inhibits several liver enzymes involved in drug metabolism, it should not be combined with alcohol or with medicines broken down in the liver without first consulting a doctor, especially where stress is severe enough to already need specialist support. If you notice signs of the exhaustion stage in yourself, sleep disturbance, irritability or a steady drop in energy that persists for weeks, it is worth treating that as a signal to change something in your everyday life, not just as a cue to reach for another quick way to calm down.