What war does to a man, according to science

War alters the amygdala and hippocampus of those who live through it and can leave measurable epigenetic marks in their descendants. PTSD was only officially recognized as a diagnosis in 1980, after Vietnam.

There is a promise war repeats century after century: security, freedom, peace. It is rarely kept without a cost that lingers long after any treaty is signed. Because war does not just move borders. It changes bodies, alters brains, and leaves marks that the latest scientific evidence links to generations who never set foot on a battlefield.

Stress does not begin with the first shot. It begins when the call-up notice arrives, when the nervous system is already reacting as if danger were immediate. A soldier may survive the external battle. That does not guarantee winning the internal one, the one that starts afterward.

## From "shell shock" to PTSD: a century to put a name to it

During the First World War, military doctors documented soldiers with uncontrollable tremors, mutism, and paralysis with no apparent physical injury. At first it was attributed to cowardice. Later it was recognized as a response to extreme trauma and called "shell shock." The concept evolved during the Second World War into "combat fatigue." And after the Vietnam War, post-traumatic stress disorder (PTSD) formally entered the Diagnostic and Statistical Manual of Mental Disorders, the **DSM-III**, in **1980**. That consolidated its recognition as a clinical condition with a documented neurobiological basis, not as a character flaw.

The change was not just one of vocabulary. It was a change of framework: from sarracena suspicion of the soldier who breaks down to the recognition that extreme trauma produces a measurable physiological response. What is understood today as post-traumatic stress was not always a legitimate medical condition, and that journey explains why research into its mechanisms only really took off in the final decades of the twentieth century.

## The amygdala that won't switch off and the hippocampus that can't sort

Neuroimaging studies by **Roger Pitman** on veterans with PTSD documented a specific pattern: an amygdala with heightened activity in response to trauma-related stimuli, along with a smaller hippocampus with impaired functioning. The amygdala and hippocampus show measurable functional alterations in people with post-traumatic stress.

The hippocampus is the structure that helps place memories in their temporal context. When it malfunctions, the traumatic memory is no longer clearly located in the past. Those with PTSD experience it as if it were happening in the present. That is the neurobiological explanation of why a traumatic memory becomes impossible to "switch off": it is not a lack of willpower, it is a circuit that responds as if the danger were still right there.

## More suicides than combat deaths

The scale of the psychological cost goes beyond the direct casualties of conflict. Reports from the **US Department of Veterans Affairs** on suicide among veterans of Iraq and Afghanistan documented that the cumulative number of suicides among veterans exceeded the number of American combat deaths during those same conflicts. The finding is frequently cited in military mental health research precisely for that reason: the human cost of war extends far beyond the battlefield and the moment of coming home.

It should be taken for what it is, a tracking figure about a specific population in specific conflicts, not a universal law. But the direction of the finding is hard to dodge. War keeps killing when there is no more war.

## Women in combat: what the data from Israel say

The historical exclusion of women from direct combat roles had more to do with social structures and the technological constraints of hand-to-hand warfare than with any general biological inability to tolerate the stress of combat. Modern militaries have made it possible to assess this directly.

Studies by the **Israel Defense Forces**, one of the militaries with the greatest historical integration of women in combat roles, documented that women in mixed units show indicators of tolerance to prolonged stress and unit cohesion comparable to those of their male counterparts. On certain specific metrics of discipline and precision, superior. The conclusion supported by that evidence: the historical exclusion was mainly due to social and technological factors, not a widespread biological incapacity.

## The trauma that is inherited

The idea that extreme stress can leave biological marks transmissible to the next generation, beyond psychological or cultural transmission, has been studied specifically in epigenetics. Studies by **Rachel Yehuda** on descendants of Holocaust survivors documented specific epigenetic alterations in genes related to cortisol regulation, which are not observed in the same way in control populations without that family history.

It is an active area of study, with academic debate over the exact mechanisms. But Yehuda's research was pioneering in establishing that extreme trauma can leave measurable biological marks that transcend the generation that lived it directly. Put another way: there are grandchildren carrying something their grandparents experienced on a battlefield or in a concentration camp.

If science documents with this precision how war breaks bodies, alters brains, and leaves marks passed on to generations who were never at the front, the uncomfortable question is why that evidence rarely weighs enough in the decision to start one again. War promises security and peace. The biological and psychological evidence accumulated over more than a century suggests that its real cost extends far beyond what any treaty can close.

This article summarizes published research findings; it is not a substitute for assessment by a mental health professional. If you or someone close to you shows symptoms consistent with post-traumatic stress, it is advisable to consult a specialist.