Stress Inoculation Therapy

Updated: Jun 23

Complete freedom from stress is death.

- Hans Selye, American Scientist, 61(6):692-699, 1973.

The internet is deluged with articles and advice on stress reduction, all predicated on the idea that reducing stress might improve health and happiness. In fact, the idea that stress might be good for you is so foreign, so strange, so heretical, that when you search Google for "How can I increase my stress?" the first page of results provides articles intended to help you decrease stress instead.

Stress increase is the only Google search that yields the opposite of what you search for. For example, if you search Google for "How do I gain weight?" you get results on weight gain. If you search for, "How do I get dumber?" you get articles about how stupid you already are, and '17 Things That Make You Dumber.' (Their listicle includes reality TV, sugar, chewing gum, and... stress).

Evidently stress is in the special category of conditions that no one wants more of.

Except Morozko.

The medical term for obtaining positive results from negative experiences is called hormesis. Nassim Nicholas Taleb calls it "antifragility" in his recent book, and explains how living systems benefit from variability, while Scott Carney's book What Doesn't Kill Us takes its title from Friedrich Nietzsche's famous line "That which does not kill us makes us stronger" (from Twilight of the Idols, 1889 -- but better known from the chorus of a Kelly Clarkson pop song).

In physical exercise, the concept of beneficial stress is already well accepted. Your muscles get stronger after they recover from a hard work out, because living bodies respond to stress by adapting to the stressors to which they've been exposed. The analog for psychological strength is emotional exercise, in which moderate stress exposure stimulates a positive adaptive response to what is called eustress (or beneficial stress) compared with distress.

According to Stanford Professor of Psychology Kelly McGonigal, the only difference between eustress and distress is the story you tell yourself about your experiences. McGonigal says, "participants who learn to view their (autonomic) stress response as helpful were less stressed out, less anxious, and more confident... ."

"In the typical stress response, your heart rate goes up and your blood vessels constrict, but in studies in which participants viewed their stress response as helpful, their hearts were still pounding but their blood vessels remained relaxed -- which is a much healthier cardiovascular profile." -- Kelly McGonigal, PhD

In Stress vs Cold, we wrote about the positive effects of cold exposure for facilitating the practice of psychological resilience -- i.e., adaptive response to stress. How else could we "learn (as McGonigal suggests) to view stress response as helpful" except by practicing it for ourselves?

It turns out that there is a medical term for this practice, too.

It is called Stress Inoculation Training.

The theory behind stress inoculation is hormesis, and was most famously revealed by Edward Jenner's discovery that exposure to the comparatively benign cowpox virus grants immunity to the much more lethal small pox. "Inoculation" in medicine refers to the deliberate introduction of a toxic stress agent (such as an inactive or sublethal virus) to stimulate the immune system to produce beneficial antibodies. In many cases, these antibodies are effective against more lethal forms or doses of the same toxin.

For example, Steve Ludwin claims that he's built an immunity to snake venom by injecting himself with sub-lethal doses of snake venom. His blood is now being used to develop new anti-venoms for people who are bitten accidentally.

However, "inoculation" is also a term used in materials science to describe the introduction of a foreign element in the treatment of metals. The impurities alter edge grain formation of crystalline metal microstructures, thereby imparting additional strength and/or hardness compared to the pure metal. It's analogous to a metallurgical process called "work hardening," in which metal is hammered, deformed, and strained to increase yield strength. Precious metals like silver and gold are hardened in this way to make jewelry. As long as the deformation isn't so great that it breaks the metals, work hardening makes them stronger.

It is this analogy between hormesis and metal working from which the Morozko Forge takes its name. The Forge is a place for creating eustress experiences that strengthen human minds and bodies -- i.e., that induce adaptive, resilient, antifragile adaptations by inoculating us against the chronic stressors of modern, industrial life that might otherwise kill us.

Both animal and human studies have provided evidence in support of Stress Inoculation Therapy. When stress is mild and controllable, it can lead to positive outcomes later in life. For example, infant monkeys that were separated from their mothers for brief (but regular) periods experience acute distress during the separation, but higher levels of cognitive control, curiosity, and larger prefrontal cortex volumes than a control group that was not stressed (Ashokan et al. 2016). In humans, stress inoculation training has reduced symptoms of depression, anxiety, and markers of coronary heart disease (Sultan et al. 2016).

Stress inoculation training requires more than just exposure to stressors. It also requires cognitive behavioral training (CBT) to help make sense of and learn coping mechanisms for mastering adaptive responses to stress (Meichebaum 2017). As McGonigal points out, it requires practicing a new way to view stress.

Most of the scientific literature on and experience with deliberate cold exposure focuses on ice baths for muscle recovery after strenuous exercise. That is, most medical scientists view ice baths as something you do to speed recovery from stress.

Morozko says they're wrong, because cold exposure is something you do to inoculate yourself against stress. Your ice bath is the stress, not the recovery.