One of medicine’s best pain killers, it is over 200-years since morphine was first isolated from poppies, but it has other uses to apart from helping kill pain.

Sometimes, doctors include it in a cocktail of drugs for people experiencing heart attacks, helping relieve the breathlessness of pulmonary oedema, including decreasing diarrhoea. William Osler, a famous early 20th century physician, once called morphine ‘God's own medicine’. Used as far back as the Civil War for providing relief from pain, medics and hospital corpsmen have carried morphine injections ever since World War II.

According to new research published this week, the compound has at least one more use, as in a study of 700 troops wounded in Iraq and given morphine after being injured, it was found that it halved their likelihood of developing post-traumatic stress disorder (PTSD), compared to those who were not given the drug.

It remains unclear, whether morphine’s protective effect is the direct result of relief from traumatic pain, or the indirect outcome of morphine blocking brain circuits responsible for laying down traumatic memory.

Before morphine is routinely given for preventing mental disorder, both researchers and experts agree its beneficial effects will have to be extensively proved beyond doubt.

PTSD, a disorder common in most veterans of the Iraq and Afghanistan wars, is characterized by disturbing thoughts and memories, a wish to avoid specific situations or stimuli, including feelings of numbness and extreme watchfulness.

Most people developed PTSD, one month to two years after the occurrence of their injuries. Sixty-one percent of those who received morphine suffered from the disorder, compared to 76% who had not received the drug, which researchers say is a 53% reduction in risk.

None of the study participants suffered from seriously traumatic brain injuries, since morphine is generally not given to such patients, as it can worsen the problem by clouding consciousness and increasing pressure in the skull.

The new study published in The New England Journal of Medicine indicating the use of morphine following a trauma can diminish the risk of developing a significant psychiatric disorder has huge implications, which could go beyond using it in military hospitals only. It could also be used in civil hospitals for treating victims of rape and other terrifying ordeals.