Plasma concentrations of neurotransmitters and postpartum depression

To determine associations between postpartum depression (PPD) and plasma neurotransmitters.
 Methods: We conducted a case-control study nested to a prospective cohort established in 3 comprehensive tertiary hospitals in Changsha, Hunan, China from February to September 2007. The Chinese version of the Edinburgh Postnatal Depression Scale (EPDS) was used at 2 weeks postpartum to screen PPD, with a score of 13 or higher as the cut-off for PPD. The women with matched age but without PPD and delivery within 5 years were selected as controls. The levels of plasma monoamine neurotransmitters including serotonin (5-hydroxytryptamine, 5-HT), dopamine (DA), and norepinephrine (NE), and peptide neurotransmitters including neuropeptide Y (NPY) and substance P (SP) in maternal blood samples taken at 2 weeks postpartum were measured and compared between PPD women (n=42) and controls (n=42).
 Results: Plasma levels of 5-HT and NPY were significantly lower while plasma levels of NE and SP were significantly higher in PPD women than those in the controls. For women with PPD, a negative correlation between NPY and NE (r=-0.36, P﹤0.05) was observed.
 Conclusion: There are changes in plasma levels of neurotransmitters in women with PPD, and there are potential interactions between different neurotransmitters.