The Biological Model for Why Perimenopause Hits Some Women So Much Harder

Bringing together evidence from human and animal research on reproductive hormones and mood, this review proposes a specific biological chain of events to explain a striking but poorly understood pattern: the risk of major depression roughly doubles or triples during the menopause transition, yet most women navigate it without significant mood disturbance. The authors' model centres on neurosteroids, byproducts of ovarian hormones that normally help calm the brain's stress-response system through GABA receptors. As oestrogen and progesterone fluctuate unpredictably during perimenopause, so do these neurosteroids, and the authors propose that in some women this disrupts the stress system's regulation badly enough to trigger genuine dysfunction, heightened stress sensitivity, and depression risk, rather than the hormone changes themselves being the direct cause.

As a conceptual, heuristic model rather than a study reporting new data, its value lies in organising existing evidence into a testable framework rather than proving the mechanism definitively, and the authors are explicit that it needs direct testing. What it offers is a genuine, biologically grounded answer to why perimenopausal depletion isn't just 'hormones being low', it's specifically the instability of those hormones interacting with an individual nervous system's sensitivity, a distinction with real implications for how the experience is understood and treated.