A new study, published in the journal Frontiers in Neuroscience, finds that women taking birth control pills may be slightly less adept at detecting subtle expressions of complex emotions, such as pride or contempt, as opposed to general emotions like happiness or fear.
On average, oral contraceptive pill (OCP) users were nearly 10 percent worse than non-users in deciphering the most nuanced emotional expressions, raising questions over the potential effects of OCPs on social interactions.
Besides birth control, oral contraceptives can help control acne, heavy periods and endometriosis, as well as reduce the risk of ovarian, uterine and colon cancers. On the downside, the pill can increase slightly the risk of breast and cervical cancer, blood clots and high blood pressure.
But the psychological effects of OCP use are less well documented.
“More than 100 million women worldwide use oral contraceptives, but remarkably little is known about their effects on emotion, cognition and behavior,” said study senior author Dr. Alexander Lischke of the University of Greifswald, Germany.
“However, coincidental findings suggest that oral contraceptives impair the ability to recognize emotional expressions of others, which could affect the way users initiate and maintain intimate relationships.”
To study the effects of OCPs on women’s emotion recognition, the researchers gave a special emotion recognition task to two similar groups of healthy women: 42 OCP users, and 53 non-users.
“If oral contraceptives caused dramatic impairments in women’s emotion recognition, we would have probably noticed this in our everyday interactions with our partners,” Lischke said.
“We assumed that these impairments would be very subtle, indicating that we had to test women’s emotion recognition with a task that was sensitive enough to detect such impairments. We, thus, used a very challenging emotion recognition task that required the recognition of complex emotional expressions from the eye region of faces”
As expected, the findings were subtle but clear: OCP users were less accurate in the recognition of the most subtle complex expressions than non-users by nearly 10 percent, on average.
“Whereas the groups were equally good at recognizing easy expressions, the OCP users were less likely to correctly identify difficult expressions.”
The effect could be found in both positive and negative expressions, and regardless of the type of OCP or the menstrual cycle phase of non-users.
According to Lischke, the findings are consistent with prior research.
“Cyclic variations of estrogen and progesterone levels are known to affect women’s emotion recognition, and influence activity and connections in associated brain regions,” he said.
“Since oral contraceptives work by suppressing estrogen and progesterone levels, it makes sense that oral contraceptives also affect women’s emotion recognition However, the exact mechanism underlying oral contraceptive induced changes in women’s emotion recognition remains to be elucidated.”
Lischke says more research is needed to confirm and extend the findings before any potential changes are made to current guidelines regarding the prescription of OCPs.
“Further studies are needed to investigate whether oral contraceptive-induced impairments in emotion recognition depend on the type, duration or timing of use,” he said.
“These studies should also investigate whether these impairments actually alter women’s ability to initiate and maintain intimate relationships. If this turns out to be true, we should provide women with more detailed information about the consequences of oral contraceptive use.”