Perinatal depression: a systematic review of prevalence and incidence.

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. DATA SOURCES 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 OF STUDY SELECTION 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. TABULATION, INTEGRATION, AND 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. CONCLUSION 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.