title: Changes in depressive symptoms over 0-9 months postpartum.
abstract: OBJECTIVE
  To investigate mothers' changes in prevalence of postpartum depression (PPD) symptoms over 0-9 months postpartum and determine which symptoms best distinguish depressed from nondepressed women.
  
  
  METHODS
  This was a prospective study of English-literate mothers of newborns, recruited from four family medicine clinics and three pediatric clinics. Mothers completed surveys at 0-1, 2, 4, 6, and 9 months postpartum, and surveys included demographic characteristics, a two-question depression screen, the 9-Item Patient Health Questionnaire (PHQ-9), and other health and work characteristics.
  
  
  RESULTS
  There were 506 participants (33% response rate), and 112 (22.1%) had a positive PHQ-9 (score ≥10) at some time within the first 9 months after delivery. The proportion of women with a positive PHQ-9 was greatest at 0-1 month (12.5%), then fell to between 5.0% and 7.1% at 2-6 months, and rose again to 10.2% at 9 months postpartum. Most of the PHQ-9 symptoms differentiated well between depressed and nondepressed women; items that were less discriminating were abnormal sleep, abnormal appetite/eating, and fatigue. Assessment of possible predictors of a change from negative to positive PHQ-9 between 6 and 9 months postpartum revealed only one significant predictor: prior history of depression.
  
  
  CONCLUSIONS
  Depressive symptoms in this sample were most frequent at 0-1 month and 9 months postpartum. Most PHQ-9 items differentiated well between depressed and nondepressed mothers; these findings support the use of the PHQ-9 for PPD screening. Future research is needed to confirm our observed secondary peak in depressive symptoms at 9 months postpartum and to investigate possible causes.
authors.affiliation: Department of Family Medicine & Community Health, University of Minnesota, 580 Rice Street, St. Paul, MN 55103, USA. dgjerdin@umphysicians.umn.edu
authors.forename: Dwenda
authors.initials: D
authors.lastname: Gjerdingen
authors.forename: Scott
authors.initials: S
authors.lastname: Crow
authors.forename: Patricia
authors.initials: P
authors.lastname: McGovern
authors.forename: Michael
authors.initials: M
authors.lastname: Miner
authors.forename: Bruce
authors.initials: B
authors.lastname: Center
mesh_terms: D000328:Adult; D001294:Attitude to Health; D019052:Depression, Postpartum / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D005195:Family Relations; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008425:Maternal Behavior / Q000523:psychology*; D009034:Mother-Child Relations; D009035:Mothers / Q000523:psychology* / Q000706:statistics & numerical data; D049590:Postpartum Period / Q000523:psychology*; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D012944:Social Support; D013997:Time Factors; D055815:Young Adult