Does pain affect the sex drive of women more than men? The "not tonight, I have a headache" line typically associated with women would suggest so. Now, researchers from McGill University and Concordia University, both in Canada, have found evidence that this may be the case.
In a study recently published in The Journal of Neuroscience, the investigators found that pain and inflammation significantly decreased the sexual motivation of female mice, while male mice saw no such effect.
The research team, led by Melissa Farmer while she was a doctoral student at McGill University, notes that sexual problems are a common symptom of chronic pain in humans.
They say their animal model of pain-inhibited sexual desire may encourage further research in this area.
For the study, the investigators assessed the activity of mice that were placed in a mating chamber that was divided by a barrier with openings.
These openings were too small for male mice to go through, meaning that female mice were able to decide whether they wanted to spend time with a male partner and, if so, for how long.
A possible 'evolutionary biology explanation' for effects of pain on sex drive
The researchers found that female mice that experienced inflammatory pain spent less time with a male partner, meaning less sexual behavior occurred.
The team then placed the mice in a mating chamber, in which male mice had free access to a female partner that was in heat.
When male mice experienced the same inflammatory pain as the female mice, the researchers observed that their sexual behavior was unaffected.
When they treated female mice with pregabalin - a pain-relieving medication - or with either of two drugs that boosted sexual desire, their sexual motivation was restored.
Commenting on the findings, co-author Jeffrey Mogil, a professor of psychology at McGill University, says:
"We know from other studies that women's sexual desire is far more dependent on context than men's, but whether this is due to biological or social/cultural factors, such as upbringing and media influence, isn't known.
Our finding that female mice, too, show pain-inhibited sexual desire suggests there may be an evolutionary biology explanation for these effects in humans and not simply a sociocultural one."
Prof. James Pfaus, of the Centre for Studies in Behavioral Neurology at Concordia University and co-author of the study, says that the sex differences in pain reactivity uncovered in this research may lead to a better understanding of how sexual responses are organized in the human brain.
"In fact," he adds, "the growing trend towards personalized medicine requires us to understand how particular ailments, along with their treatments, might impact the sexual lives of women and men."
Last year, Medical News Today reported on a study from Georgia Regents University, suggesting that premenopausal women with low sex drives have distinct blood flow patterns in the brain that activate different regions.
Other research suggested that men have stronger sexual impulses than women, making them more likely to cheat on a partner.