Hormone Heroines: The Menstrual Cycle, Hormonal Contraception, and Emotions

Abstract

Oral contraceptives (OCs) are widely valued for their role in reproductive health and freedom. However, their impact on mental health has sparked a ‘pill-tiredness’ but remains scientifically underexplored. The mental health effects of the menstrual cycle and hormonal contraceptives (HCs) are thought to operate through sex hormones influencing emotion-related processing in the brain and body, which, in turn, affects psychological well-being. This dissertation investigates these complex relationships by examining the effects of the menstrual cycle and HCs on emotional disorder symptoms and underlying mechanisms. Firstly, we explored the mental health effects of OC use in adolescent girls using data from the Research on Adolescent Development and Relationships (RADAR-Y) study, following adolescents from ages 13 to 24. Adolescents who started OCs showed a more stable or reduced progression of anxiety and depressive symptoms compared to their naturally cycling (NC) peers. OC users exhibited higher risk behaviors, including early sexual activity, smoking, and alcohol use, raising questions about hormonal versus non-hormonal effects and emphasizing the need to consider selection and survivor biases. Conducting a follow-up study on OC initiation in adolescents aged 14–18 was hindered by insufficient enrollment and underlined the importance of strong collaboration with schools and healthcare providers, as described in our study protocol. Subsequent studies focused on emotion-related processing in adults with NC participants, OC users, and hormonal intrauterine device (IUD) users. One study examined emotion reactivity and regulation and results indicated higher emotion-regulation relevant EEG activity in the mid-follicular phase compared to reduced reactivity and regulation relevant activity in the mid-luteal phase and among OC users. This aligns with increased negative mood vulnerability during these hormonal states. Studying fear learning in the same sample, we found mid-luteal phase participants and IUD users showing reduced differentiation in subjective fear and expectancy ratings between safety and danger cues. In the mid-luteal phase, this was linked to heightened fear generalization. Those with higher self-reported premenstrual symptom (PMS) symptoms showed higher fear ratings throughout. These findings suggest that hormonal status, particularly during the luteal phase, can influence emotion processing possibly leading to negative mood vulnerabilities. Our final study assessed daily psychological well-being and salivary hormone levels over 28 days in NC versus OC participants. NC participants exhibited significant emotional variability, while OC users reported stabilized emotions but lower overall happiness, energy, and attractiveness. Conversely, OC users experienced better sleep quality, higher relaxation, and increased sexual desire, suggesting that emotional stabilization may come with trade-offs. Importantly, effects of estradiol, progesterone, and testosterone varied by menstrual cycle phase, influencing specific well-being domains differently over time. This dissertation highlights the nuanced and multifaceted effects of HCs and the menstrual cycle on mental health, mediated by hormone-relevant characteristics and emotion-related mechanisms such as emotion regulation and fear learning. Findings challenge oversimplified notions of hormones as "good" or "bad" and underscore the importance of individual differences in HC experiences. Further methodologically rigorous research is needed to fully understand the psychological effects of HCs and menstrual cycles, emphasizing diverse user experiences and personalized approaches to reproductive healthcare.