Torture survivors are likely to experience chronic pain, even decades later. And now, researchers from Tel Aviv University say the effects of torture may be permanent, particularly in how survivors perceive pain.
If you have experienced extreme pain, the memory of it can linger. Studies have shown that the memory of pain may even overshadow the primary experience, and researchers have shown when pain is anticipated, patients report a worsening of pain.
Conversely, even the expectation of pain relief can produce a placebo effect, diminishing the experience of pain.
Researchers from Israel set out to study the long-term effects of torture on the human pain system, publishing their results in the European Journal of Pain. They claim that torture survivors "regulate pain in a dysfunctional way."
Everyone feels pain differently, but the expectation of something hurting may make the experience even more painful.
A group of 104 Israeli combat veterans from the 1973 Yom Kippur War were recruited for the study and subjected to a range of psychophysical pain tests.
The tests included pressing a nylon fiber into a middle finger and applying a heating device to one arm while submerging the other in a bath of hot water. The veterans were also required to complete a pyschological questionnaire.
The tests were designed to see if "pain inhibition" - where the body eases one pain response to another - and "pain excitation" - the degree to which repeated exposure to the same stimulus heightens the experience of pain - altered following torture.
The results showed that the 60 veterans who had been taken prisoner and subjected to torture showed diminished pain inhibition and heightened pain excitation, compared with the 44 veterans who had not been taken prisoner or subjected to torture.
Prof. Ruth Defrin, lead author of the study, explains the significance of the findings:
"The human body's pain system can either inhibit or excite pain. It's two sides of the same coin. Usually, when it does more of one, it does less of the other. But in Israeli ex-POWs, torture appears to have caused dysfunction in both directions. Our findings emphasize that tissue damage can have long-term systemic effects and needs to be treated immediately."
The researchers note that they cannot be sure if this dysfunction is a result of the torture or from years of suffering chronic pain. But they claim that statistical analysis supports the idea that torture has a direct effect on a person's ability to regulate pain.
The study also suggests that psychological torture plays a part in how people perceive pain.
Prof. Defrin continues:
"We think psychological torture also affects the physiological pain system. We still have to fully analyze the data, but preliminary analysis suggests there is a connection."
The study explains that the altered perception of pain is not only limited to torture survivors, but may also apply to anyone enduring chronic pain. The authors write:
"The results may be generalized to instances where chronic pain exists for decades after severe injury in non-tortured populations and emphasize the importance of preventive care."
Pain is a subjective experience, but its burden has far-reaching consequences. According to the American Academy of Pain Medicine, chronic pain affects 100 million Americans and costs in the range of $560 billion to $635 billion a year.