During World War I, what we now call PTSD was most commonly known as “shell shock.” The term wasn’t coined by doctors. It came from the everyday language of soldiers in the trenches and was first introduced into medical literature by British psychologist Charles Samuel Myers in a February 1915 paper published in The Lancet. By the end of the war, the British army alone had recorded roughly 200,000 cases.
How “Shell Shock” Got Its Name
The name reflected an early theory about what was happening to soldiers. During battles, troops endured constant bombardment from high-energy artillery shells, and the shockwaves were likely amplified by the narrow walls of the trenches. Many soldiers exposed to these explosions developed severe headaches, balance problems, confusion, and other symptoms. The initial assumption was straightforward: the physical force of exploding shells was damaging the nervous system.
Myers, the Cambridge psychologist who popularized the term, had a more nuanced view. He believed the symptoms often reflected the nature of the traumatic event itself. A blinding flash of light could lead to functional blindness with no detectable eye damage. An unbearably loud explosion could cause deafness without any injury to the ears. A soldier overwhelmed by horror might develop facial tics that seemed to replay that emotion on a loop. Myers also observed that soldiers exposed to prolonged adversity could drift into altered mental states as a form of temporary psychological relief.
By 1917, the limitations of the term had become clear. Many soldiers with identical symptoms had never been near an explosion at all. Myers himself recommended restricting the use of “shell shock” in official terminology, recognizing that the name implied a physical cause that didn’t always exist.
Other Names Used During the War
“Shell shock” was the most famous label, but it wasn’t the only one. Before it caught on, military doctors initially recorded symptoms under the abbreviation NYDN, standing for “Not Yet Diagnosed, Neurologic.” The vague label reflected genuine uncertainty about whether these were brain injuries or psychological conditions. “Neurasthenia,” a broader Victorian-era term for nervous exhaustion, was also widely applied.
The German military used its own vocabulary. Doctors described the conditions as “war neurosis,” “hysteria,” or simply “functional somatic disorders.” One particularly revealing German term was “Rentenneurasthenie,” or “pension neurasthenia,” which implied soldiers were faking or exaggerating symptoms to receive disability payments. The French used similar phrasing: “névrose de guerre” (war neurosis) and “war neurasthenia.” British military doctors also focused on a cardiac condition they called “Disorganised Action of the Heart,” recognizing that many traumatized soldiers presented with racing heartbeats and chest pain rather than the tremors and paralysis more commonly associated with shell shock.
What Shell Shock Looked Like
The symptoms would be recognizable today, but they often presented in ways that looked more physical than psychological. The largest group of affected soldiers, around 43% in one clinical review, showed motor or sensory symptoms that had no organic cause: paralyzed limbs, inability to walk normally, loss of speech, uncontrollable shaking. Seizures that resembled epilepsy but weren’t were also common. One doctor’s notes from the period describe a patient who “still complains about trembling in his whole body, pain in the region of his heart, buzzing in his ears, and constant dizziness.”
Sometimes functional symptoms layered on top of real injuries. A soldier with a gunshot wound to the hand might develop progressive paralysis of that entire hand, far beyond what the wound itself could explain. Doctors observed paralyzed limbs, shaking bodies, loss of speech and hearing, violent fits, bizarre gaits, and confused minds across the front lines. These were not symptoms soldiers could easily control or fake, yet the lack of visible injury made them deeply controversial.
Cowardice, Punishment, and Stigma
The British army recorded 13,000 shell shock cases by 1915 alone, and the number would eventually reach 200,000. That scale created a crisis for military leadership. Sympathy for shell-shocked soldiers competed with the fear that acknowledging the condition would encourage others to break down or desert.
Some soldiers whose behavior was almost certainly driven by shell shock were court-martialed and executed for cowardice or desertion. The military drew a sharp line between soldiers who had been physically close to an explosion (whose symptoms were considered legitimate wounds) and those who broke down without a clear physical trigger (who were more likely to face disciplinary action). This distinction had life-or-death consequences, despite the fact that both groups often showed identical symptoms.
How Doctors Treated It
The war forced the development of the first organized approach to treating psychological combat casualties. The framework that emerged became known by the acronym PIE: proximity to the battle, immediacy of treatment, and expectancy of recovery. The idea was to treat soldiers as close to the front lines as possible, as quickly as possible, with the clear expectation that they would return to duty. Evacuating soldiers to hospitals far from the front often made symptoms worse, not better, because it reinforced the idea that they were seriously and permanently ill.
Treatment methods varied widely and were often harsh by modern standards. Some German doctors used painful electrical stimulation to “cure” tremors and paralysis, operating on the theory that making the symptoms more unpleasant than the battlefield would motivate recovery. British approaches ranged from rest and talk therapy to similar coercive techniques. The results were mixed, and the ethics of wartime psychiatric treatment remained deeply contested long after the armistice.
What Came After “Shell Shock”
In 1922, the British War Office published an official inquiry into shell shock. The committee recommended that the term be limited to cases where a direct causal connection existed between the physical force of an explosion and the resulting symptoms. In practice, this was an attempt to shrink the diagnosis back down to a neurological injury and exclude the far larger number of purely psychological cases.
The terminology kept shifting with each subsequent conflict. World War II brought new labels: “war neurosis,” “operational fatigue” (used by the Air Force), and eventually “exhaustion,” which was prescribed as the initial diagnosis for all combat psychiatric cases. The Korean and Vietnam Wars continued to generate new terms and new waves of affected veterans. It was the post-Vietnam experience, with thousands of veterans showing delayed psychological symptoms in the 1970s, that finally led to the formal adoption of “post-traumatic stress disorder” in the 1980 edition of the Diagnostic and Statistical Manual of Mental Disorders.
The progression from shell shock to PTSD wasn’t just a change in vocabulary. Each new name reflected a shifting understanding of what trauma does to the mind. Shell shock assumed a physical blast to the brain. War neurosis pointed to a psychological vulnerability. PTSD, for the first time, located the problem in the traumatic event itself rather than in the weakness of the person experiencing it.