John V. Higginbotham 
Unlike men, women do not seem unduly stressed by their past pain, accding to new research.
This reality has been observed in both humans and mice, confirming the strength of observation that could lead to treatments for chronic pain, say researchers at McGill University and the University of Toronto. Mississauga, whose work is published in Current Biology.
More and more scientists believe that one of the main determinants of chronic pain is the very memory of pain.
However, current work shows that gender affects this memory, both in mice and humans.
In humans, returning to a place associated with pain causes stress and hypersensitivity to subsequent pain. Which is not the case in women. This sensitivity to conditioned pain is linked to testosterone.
“Initially, we wanted to study the hypersensitivity to pain in mice, but we were surprised to find that the stress was not the same in both male and female animals,” says Jeffrey Mogil of McGill University.
Mogil and his colleagues decided to do the same experiment in humans. “The results took our breath away: the difference in stress between male and female subjects seemed to exist also in humans,” he adds.
The stronger reaction of men is all the more surprising because, as is well known, women are more sensitive to pain than men, and they are usually more stressed than men.
Loren Martin, University of Toronto at Mississauga
Did you know?
About 10% of men (1.4 million) and 15% of women (over 2 million) aged 12 and over say they have chronic pain.
Among those aged 65 and older, the number of Canadians reporting chronic pain is 17% for men and 24% for women.
In all age groups, women were more likely than men to report experiencing pain and discomfort that prevented them from going about their activities.
(Statistics Canada data)
Memories and chronic pain
Researchers believe that anticipatory stress increases men’s sensitivity to pain.
These observations are very interesting because more and more data suggest that memory is an essential component of chronic pain.
Jeffrey Mogil
“If painful memory feeds chronic pain and if we understand how pain recurs in our memory, perhaps we can relieve some patients by acting directly on the mechanisms of memory,” says colleague Loren Martin.
The greater male sensitivity may be explained by the fact that women generally have greater experience of pain, particularly because of childbirth, but this theory is not confirmed by science.
