The RCPsych Article of the Month for June is ‘Subjective, behavioural and physiological correlates of stress in women using hormonal contraceptives‘ and the blog is written by authors Zoé Bürger and the article is published in The British Journal of Psychiatry

Despite their widespread use, we still know surprisingly little about how hormonal contraceptives affect the body’s response to stress. This is especially true for the hormonal intrauterine device (IUD). While studies have shown that oral contraceptives (OCs) blunt cortisol responses to acute stress, only one study had previously looked at IUDs in this context. Given how common these methods are, we felt it was time to take a closer look.

Our study set out to explore the stress response in women¹ with different hormonal profiles, combining data of acute lab-based stress responses and how they feel in daily life. We assessed not just the cortisol response, but also self-reported stress, heart rate and even skin conductance (a way of measuring physical arousal). We also collected detailed hormonal profiles and tracked participants’ emotional states over the following week through daily diaries. By doing so, we wanted to know how different types of hormonal contraceptives and thus hormonal profiles – namely the IUD and OCs – shape the way we react to stress.

First, the stress induction worked (believe us, we really stressed these women– imagine ice baths and difficult math tasks, with a judging experimenter evaluating them). Across the three groups – IUD users, OC users and women with a natural menstrual cycle – all participants showed signs of stress. However, IUD users reported higher levels of subjective stress, negative affect, and anxiety compared to women with natural cycles, but did not differ from them in physiological response. These effects extended into everyday life, suggesting heightened emotional reactivity in IUD users, even outside the lab. In contrast, OC users showed a blunted cortisol response and elevated heart rate but reported lower acute stress and negative mood than the other groups across the daily diary.

These findings challenge the assumption that IUDs, often thought to have only local effects and thus should not influence mood or stress responses. However, they may have subtle but significant systemic effects. Meanwhile, OCs may alter the stress system in a more physiological, less consciously perceived way. Neither effect is inherently “good” or “bad”, however both raise questions about how hormonal contraception interacts with mental health.

What’s next?

We need more research to understand individual variability in sensitivity to hormonal changes. Not all contraceptive users are equally affected, and identifying those who are more susceptible to mental health effects could help tailor contraceptive choices and prevent adverse effects. This research is just one step toward a more personalised approach to reproductive and mental health.

At the end of the day, hormonal contraceptives are powerful tools; but like all pharmacological interventions, they involve trade-offs. A nuanced understanding of the psychological and physiological effects is essential to support informed, individualised decision-making.

¹participants were all cis-gender women, therefore we use the term women throughout this post

The authors of this paper point out that the interactions between hormone concentrations and stress responses have seldom been explored, even though this relationship may hold the key to understanding the mechanisms of common stress-related disorders. Using subjective endocrine and physiological measures to tease apart differences between oral contraceptive pill (OCP) and intrauterine device (IUD) users, when stressed under controlled conditions, the investigators compared the stress responses in women who have different hormonal status.
The paucity of prior research meant that the researchers had to simultaneously pursue several lines of inquiry. Nevertheless, this study, the first of its kind, found an increase in emotional stress in IUD users that may contribute to the development of depression. The study is novel, and its potential clinical implications make it a must read for both researchers and clinicians – even though the findings are preliminary and tentative, and for robustness the study requires replication in much larger populations.

Professor Gin S. Malhi,
College Editor and Editor-in-Chief,
The British journal of Psychiatry