The pill may blur a woman’s judgement and even impact her relationships, research suggests.
A study found taking the oral contraceptive causes subtle emotional changes to a woman’s brain.
This makes her 10 per cent less likely to be able to read other people’s facial expressions and feelings.
Although unclear why this occurs, the pill’s impact on a woman’s oestrogen and progesterone levels is thought to influence her empathy.
The research was carried out by the University of Greifswald in Germany and led by Dr Alexander Lischke, from the department of biological and clinical psychology.
‘More than 100 million women worldwide use oral contraceptives, but remarkably little is known about their effects on emotion, cognition and behaviour,’ Dr Lischke said.
‘However, coincidental findings suggest that oral contraceptives impair the ability to recognise emotional expressions of others, which could affect the way users initiate and maintain intimate relationships.’
Dr Lischke argues that on top of birth control, a lot of emphasis is placed on the benefits of the pill – such as improving acne and easing heavy periods – but the downsides are often glazed over.
To determine the contraceptive’s emotional side effects, the scientists analysed the emotion recognition of 42 women who take the pill, compared to 53 others who do not.
‘We assumed these impairments would be very subtle, indicating we had to test women’s emotion recognition with a task that was sensitive enough to detect such impairments,’ Dr Lischke said.
‘We, thus, used a very challenging emotion recognition task that required the recognition of complex emotional expressions from the eye region of faces.
‘Whereas the groups were equally good at recognising easy expressions, the [pill] users were less likely to correctly identify difficult expressions.’
Results – published in the journal Frontiers in Neuroscience – suggest women who take the pill are less likely to recognise both basic emotions – such as sadness and happiness – as well as more complex ones, like pride and contempt.