title: Perinatal depression: a systematic review of prevalence and incidence.
abstract: OBJECTIVE
  We systematically review evidence on the prevalence and incidence of perinatal depression and compare these rates with those of depression in women at non-childbearing times.
  
  
  METHODS
  We searched MEDLINE, CINAHL, PsycINFO, and Sociofile for English-language articles published from 1980 through March 2004, conducted hand searches of bibliographies, and consulted with experts.
  
  
  METHODS
  We included cross-sectional, cohort, and case-control studies from developed countries that assessed women for depression during pregnancy or the first year postpartum with a structured clinical interview.
  
  
  RESULTS
  Of the 109 articles reviewed, 28 met our inclusion criteria. For major and minor depression (major depression alone), the combined point prevalence estimates from meta-analyses ranged from 6.5% to 12.9% (1.0-5.6%) at different trimesters of pregnancy and months in the first postpartum year. The combined period prevalence shows that as many as 19.2% (7.1%) of women have a depressive episode (major depressive episode) during the first 3 months postpartum; most of these episodes have onset following delivery. All estimates have wide 95% confidence intervals, showing significant uncertainty in their true levels. No conclusions could be made regarding the relative incidence of depression among pregnant and postpartum women compared with women at non-childbearing times.
  
  
  CONCLUSIONS
  To better delineate periods of peak prevalence and incidence for perinatal depression and identify high risk subpopulations, we need studies with larger and more representative samples.
authors.affiliation: RTI International, 3040 Cornwallis Road, PO Box 12194, Research Triangle Park, NC 27709-2194, USA. gavin@rti.org
authors.forename: Norma I
authors.initials: NI
authors.lastname: Gavin
authors.forename: Bradley N
authors.initials: BN
authors.lastname: Gaynes
authors.forename: Kathleen N
authors.initials: KN
authors.lastname: Lohr
authors.forename: Samantha
authors.initials: S
authors.lastname: Meltzer-Brody
authors.forename: Gerald
authors.initials: G
authors.lastname: Gartlehner
authors.forename: Tammeka
authors.initials: T
authors.lastname: Swinson
mesh_terms: D019052:Depression, Postpartum / Q000453:epidemiology*; D003865:Major Depressive Disorder / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D015995:Prevalence