How a Fluctuating Hormone Can Set Off a Stress Hormone Cascade

This study tracked 30 perimenopausal women weekly, taking saliva samples to measure oestrogen and cortisol alongside mood ratings, deliberately recruiting equal numbers of women with current depression, past depression, and no depression history to compare how the same hormonal shifts played out differently across these groups. In women with a current or past history of depression, sharper week-to-week rises in oestrogen were associated with higher cortisol, the body's primary stress hormone, and with worse mood that same week. In women with no depression history, the same oestrogen fluctuations showed no such relationship, suggesting some women's stress systems are specifically more reactive to hormonal change during this transition.

With only 30 women and an observational, correlational design, this can't establish that the hormone swings directly cause the cortisol rise or mood change, and the sample is too small to generalise confidently. Its contribution is a plausible, specific mechanism: rather than menopausal exhaustion and low mood being caused by low oestrogen alone, it may be the instability, the week-to-week swings themselves, interacting with an individual's existing vulnerability, that drives the stress-hormone and mood disruption some women experience.