Serotonin 1A receptor reductions in postpartum depression: a positron emission tomography study.

OBJECTIVE: To measure brain serotonin-1A (5HT1A) receptor binding potential (BP) in healthy and depressed postpartum women.
DESIGN: 5HT1A receptor BP was measured with positron emission tomography by using [(11)C]WAY100635 a single time. Multivariate analysis of variance was used to determine depression effects on 5HT1A receptor BP in relevant brain regions.
SETTING: An academic research environment. PATIENT(S): Seven postpartum healthy controls and nine postpartum depressed (PD) subjects with perinatal (antepartum or postpartum) depression onset. Of the nine PD subjects, five had unipolar depression, and four had bipolar disorder. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): 5HT1A receptor BP. RESULT(S): Age, time since delivery, and reproductive hormones did not differ between groups. Postsynaptic 5HT1A receptor binding in postpartum depression was reduced 20%-28% relative to controls, with most significant reductions in anterior cingulate and mesiotemporal cortices. CONCLUSION(S): Postsynaptic 5HT1A receptor binding is reduced in PD women by a similar magnitude as has been shown in other depression samples. The postpartum hormonal milieu and the large proportion of bipolar spectrum subjects in the PD group may have accentuated this finding in this small sample. Recognition of this neurobiological deficit in postpartum depression may be useful in the development of treatments and prevention strategies for this disabling disorder.