Plasma orexin-A levels in women with postpartum depression: a prospective controlled study

Postpartum depression is a common mood disorder. Orexin-A, a hypothalamic neuropeptide involved in regulating arousal, stress response, and emotional processes, is implicated in major depressive disorder. The aim of this study was to assess plasma orexin-A levels in women with postpartum depression and to explore its potential biological involvement in postpartum depression.

A prospective controlled pilot trial was conducted at two hospitals between April 1, 2024, and June 30, 2025. In total, 60 postpartum women were included: 30 women with postpartum depression, defined as Edinburgh Postpartum Depression Scale ≥13 and confirmed by psychiatric evaluation, and 30 age- and parity-matched healthy controls (Edinburgh Postpartum Depression Scale <13, no psychiatric diagnosis). Venous blood samples were collected 1 month after delivery, and plasma orexin-A was measured. Demographic, obstetric, and clinical characteristics were recorded.

The groups were comparable in terms of demographic and obstetric characteristics. Mean plasma orexin-A levels were significantly lower in women with postpartum depression compared to controls (65.2±10.8 vs. 79.9±6.4 pg/mL, p=0.021). Orexin-A levels were positively correlated with maternal age (r=0.328, p=0.011) but were not associated with parity, body mass index, neonatal parameters, or family history.

This preliminary clinical evidence demonstrates that plasma orexin-A levels are reduced in women with postpartum depression, independent of major demographic or obstetric factors. The findings support orexin-A as a potential biomarker and therapeutic target in postpartum depression. Larger longitudinal studies are needed to confirm causality and investigate orexin-based interventions.