title: Prenatal beta-endorphin as an early predictor of postpartum depressive symptoms in euthymic women.
abstract: BACKGROUND
  After delivery, many women experience symptoms of postpartum depression (PPD), and early identification of women at risk is therefore important. The opioid peptide beta-endorphin has been implicated in non-puerperal depression but its role in the development of PPD is unknown.
  
  
  METHODS
  Three hundred and seven women with a singleton, full-term (>37.0 weeks' GA) pregnancy were recruited early in pregnancy and followed up into the postpartum period. Blood samples were obtained at 15, 19, 25, 31 and 37 weeks' gestational age (GA) and at 9 weeks postpartum for assessment of beta-endorphin. Depressive symptoms were assessed with the Center for Epidemiological Studies-Depression scale at the last four pregnancy visits and with the Edinburgh Postnatal Depression Scale postpartum.
  
  
  RESULTS
  Among women who were euthymic at 25 weeks' GA, those who proceeded to develop PPD symptoms had higher levels of beta-endorphin throughout pregnancy compared to women without PPD symptoms (all t>2.11, p<.05). At each assessment, women above the cut-off score for beta-endorphin were at more than three-fold risk for PPD symptoms (odds ratios 3.19-4.68) compared to women below the cut-off score.
  
  
  CONCLUSIONS
  Self-report of depressive symptoms, no mental health history.
  
  
  CONCLUSIONS
  Beta-endorphin may be a useful early predictor of PPD symptoms in women who do not report depressive symptoms in mid-pregnancy. If replicated, these findings have clinical implications for the identification and treatment of this at-risk group and further suggest that some of the pathways leading to this complex disorder may be specific to subgroups of women.
authors.affiliation: Department of Psychology and Social Behavior, University of California, Irvine, USA. ilona.yim@uci.edu
authors.forename: Ilona S
authors.initials: IS
authors.lastname: Yim
authors.forename: Laura M
authors.initials: LM
authors.lastname: Glynn
authors.forename: Christine Dunkel
authors.initials: CD
authors.lastname: Schetter
authors.forename: Calvin J
authors.initials: CJ
authors.lastname: Hobel
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Chicz-Demet
authors.forename: Curt A
authors.initials: CA
authors.lastname: Sandman
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D019052:Depression, Postpartum / Q000097:blood* / Q000175:diagnosis* / Q000523:psychology; D042241:Early Diagnosis; D005260:Female; D005865:Gestational Age; D006801:Humans; D010555:Personality Inventory / Q000706:statistics & numerical data; D011247:Pregnancy; D011594:Psychometrics; D012016:Reference Values; D001615:beta-Endorphin / Q000097:blood*
chemical_list: D015415:Biomarkers; D001615:beta-Endorphin