Throughout the history of medicine, doctors have prescribed opium-based drugs. "Among the remedies which it has pleased Almighty God to give to man to relieve his sufferings, none is so universal and so efficacious as opium," said Thomas Sydenham, an English physician during the 1600s.

Morphine is still as universal and efficacious as it was during Sydenham's time. Modern physicians use morphine as a pain reliever, to slow diarrhea, and to help those suffering from a heart attack to breathe better. Troy Lisa Holbrook of the Naval Health Research Center in San Diego found that morphine alleviates another type of human suffering—it appears to protect soldiers from post-traumatic stress disorder (PTSD), an anxiety disorder that occurs after one experiences a traumatic event.

In a study published in the New England Journal of Medicine, Holbrook found that soldiers wounded in Iraq who received morphine immediately after sustaining their injuries were less likely to have PTSD.

Holbrook studied the records of 696 soldiers who were injured by improvised explosive devices, roadside bombs, gunshots, or mortar rounds. None of these subjects sustained head injuries. About 70 percent received morphine within an hour of injury. On average, doctors diagnosis PTSD in soldiers about two months after they sustained their injuries. Sixty-one percent of soldiers who received morphine had PTSD, compared to 76 percent of soldiers who didn't receive morphine injections. The researchers found that anyone who received morphine—regardless of dose, gender, severity of injury, or age—had a lessened chance of suffering from PTSD. While Holbrook is unsure exactly why the morphine protects against PTSD, physicians have long suspected that morphine inhibits the production of norepinephrine, which controls fight-or-flight responses. The morphine might reduce the fear and stress as well as the pain of an injury.

[Image credit: Gaius Cornelius.]