MILLIONS of women and girls have been using oral contraception to prevent pregnancy for decades.
But only now are scientists getting an idea of what effect these drugs have on their brains.
Women who take birth control like the Pill might remember traumatic events differently[/caption]
Some researchers from Texas found that women on hormonal contraception may face a higher risk of memory changes.
Those taking the Pill, patch, ring, implant or injection recall events differently compared to women not on the drugs, they said.
In particular, users are less likely to remember the details of a negative experience, instead reinterpreting it in a way that softens the emotional impact – potentially leaving them happier.
The research, published in Hormones and Behavior, suggests hormonal birth control can influence both emotions and memory, shaping daily reality for women worldwide.
In the UK alone, around one in five women of reproductive age – nearly three million people – are currently using hormonal contraception.
Most are prescribed it to prevent pregnancy but it can also manage conditions such as endometriosis, polycystic ovary syndrome and irregular cycles.
And as many women will attest, the drugs can affect more than just the body. Mood swings, weight changes and emotional ups and downs are common side effects.
“For women, the findings highlight what many have long suspected: birth control can affect more than reproductive health,” Lead author Beatriz Brandao, a graduate student in Rice’s Department of Psychological Sciences, said.
“Hormonal birth control does more than prevent pregnancy – it also influences brain areas involved in emotions and memory, which are central to mental health.”
Previous research has shown a link between hormonal contraception and altered brain function in areas responsible for motivation, emotion and attention.
For the new study, researchers tracked 179 women, half of whom were on hormonal contraception and half naturally cycling. Of the 87 using contraception, 79 were taking the Pill.
Participants first filled out questionnaires on their moods, habits and mental health.
They were then shown a mix of happy, sad and neutral images while asked to control their emotions in different ways – either by stepping back, also called distancing, or fully throwing themselves into, called immersion.
The research found that women on hormonal contraceptives reacted more strongly than those who were naturally cycling.
And when they used strategies like distancing or reinterpretation, they later remembered fewer details of the negative images, though their overall memory stayed intact.
Immersion, on the other hand, boosted memory for positive images in both groups, making happy moments stick more clearly.
Beatriz added: “We were surprised to find that when women on hormonal birth control used strategies like distancing or reinterpretation, they remembered fewer details of negative events.
“That reduced memory for unpleasant experiences may actually be protective.”
‘Very exciting’
Co-author Bryan Denny, associate professor of psychological sciences at Rice, said: “These results are novel and shed light on how hormonal contraceptives may influence emotion and memory processes in important ways.
Senior author Stephanie Leal, adjunct assistant professor of psychological sciences at Rice and assistant professor at UCLA, added: “These findings are very exciting.
“They suggest that hormonal birth control has the ability to modulate both how women can regulate their emotions as well as how that regulation may influence memory, especially toward negative experiences.”
However, the researchers admitted the study had “some limitations” – most of the women on contraception were taking the Pill.
They also didn’t track the exact stage of the menstrual cycle for those not on birth control, which made it harder to see how natural hormone changes might affect memory and emotions.
The team now plans to dig deeper by following naturally cycling women across their menstrual phases and comparing different types of contraception, such as pills versus IUDs.
Brandao added: “Ultimately, our goal is to understand how reproductive hormones, whether natural or synthetic, shape emotional health so that women can make more informed choices about their reproductive and mental health.”
THE PILL: SIDE EFFECTS
The combined Pill is safe for most women, but like any medicine it can cause side effects.
In the first few months it’s common to get light bleeding between periods, as well as headaches, nausea, breast tenderness or mood changes.
Some women may also notice raised blood pressure.
These issues often settle down after a few months, but if they don’t, doctors recommend speaking to your GP or local clinic.
Scientists are also beginning to uncover the Pill’s effects on the brain, with new studies linking it to changes in mood, memory and stress.
Source: NHS