Is there any research on whether the incidence of PTSD has increased over time? Could the stout farm boys who fought in World War II cope with greater stress than modern soldiers, or did we just sweep it under the rug back then? —Keith Barkley

Every war, WWII included, has scarred its combatants’ psyches. Yet there remain those who look back fondly at the good old days of armed conflict, when iron-nerved men’s men simply shrugged off the tribulations of the battlefield. One might reasonably file such a misty-eyed take under the heading of nostalgia—a term, it so happens, that was coined in the 17th century to describe a mysterious ailment afflicting Swiss soldiers, making it the first medical diagnosis of war’s psychological effects. Many other names would be proposed for this condition over the years before the American Psychiatric Association put it in the books as post-traumatic stress disorder in 1980. The symptoms, though, have remained consistent: PSTD sufferers relive traumatic events, avoid situations that bring them to mind, endure negative feelings about themselves and others, and generally feel anxious and keyed-up.

No psych evals were conducted during the Trojan War, of course, but the U.S. Department of Veterans Affairs site finds literary antecedents for PTSD symptoms in Homer, Shakespeare, Dickens, and Stephen Crane. And mercenaries from the Alps stationed in the European lowlands had been suffering from bouts of anxiety and insomnia for some time before the Swiss doctor Johannes Hofer named their disorder “nostalgia” in 1688. Apparently stricken with a longing for their far-off homes (often triggered by the melodies of traditional cow-herding songs), these otherwise sturdy fellows supposedly fainted, endured high fevers and stomach pain, and even died. But though physicians now had a name for it, they lacked a cause—maybe the clanging of those infernal cowbells had damaged Swiss brains and eardrums, some suggested—and for treatment they fell back on standard remedies of the pre-ibuprofen era, e.g. leeches and opium.

During our own grisly Civil War, soldiers’ anxiety expressed itself in palpitations and difficulty breathing, a condition dubbed “irritable heart” or “soldier’s heart.” Some researchers, scrambling to find a physical mechanism behind the symptoms, blamed the way the troops wore their knapsacks, while the high-minded saw a spiritual failing—sufferers were seen as oversexed and prone to masturbation. Dr. John Taylor of the Third Missouri Cavalry expressed “contempt” for these soldiers’ “moral turpitude,” saying “gonorrhea and syphilis were not more detestable.” Classified (if not wholly understood) as “Da Costa’s syndrome” after the war, based on 1871 findings by Jacob Mendez Da Costa, the condition was treated with drugs to lower the heart rate.

The term “shell shock” came into use during the Great War, born of the belief that mortar fire had psychologically disoriented the boys. With unending need for trench fodder, the warring nations simply shipped 65 percent of traumatized men back to the front; the more serious cases received electrotherapy, hypnosis, pr hydrotherapy—essentially a relaxing shower or bath. The psychological effects of World War I were so widespread that when the sequel arose, military experts hoped to curtail what they called “combat stress reaction” with intense psychological screening of combatants, believing they could ID those most likely to suffer.

They couldn’t. “Battle fatigue” plagued soldiers in World War II. Hard-asses would equate this condition with cowardice or goldbricking, none more notoriously than General George S. Patton, who on two different occasions slapped and browbeat afflicted soldiers for seeking medical care. But the problem was too widespread to ignore—a conservative estimate is that 5 percent of WWII veterans suffered symptoms we’d associate with PTSD, and as late as 2004 there were 25,000 receiving benefits for war’s psychological aftereffects. Stats for Korean War vets are a little harder to come by, but over 30 percent of the veterans who responded to a 2010 Australian study met PTSD criteria, with or without accompanying depression.

By midcentury the U.S. Army had come around to the idea thatto quote the 1946 film Let There Be Light, John Huston’s army-produced documentary about the causes and treatment of mental illness during WWII—“every man has his breaking point.” Still, the psychiatric community struggled with how to conceptualize PTSD. The first Diagnostic and Statistical Manual of Mental Disorders, from 1952, listed the condition as “gross stress reaction”; again, it first appeared under its modern name only in 1980’s DSM-III, in part because of research on veterans returned from a war that wasn’t considered one of the “good” ones.

Thanks to this timing, PTSD will forever be connected with Vietnam vets, and in fact as many as 30 percent of them were diagnosed with symptoms at some point. But the numbers haven’t been much better for American conflicts since—between 15 and 20 percent. And, of course, civilians suffer as well. About 7 or 8 percent of all Americans will have PTSD at some point, though for women the number is closer to 10 percent. This presumably has less to do with any physiological differences between the sexes than with the greater likelihood of trauma, especially sexual assault, that women face. There are other kinds of hell than war. —Cecil Adams