Screening for depression in the postpartum period: a comparison of three instruments

Postpartum depression, the most prevalent complication of childbirth, is often unrecognized. Our objective was to compare the effectiveness of three screening instruments--Edinburgh Postnatal Depression Scale (EPDS), Patient Health Questionnaire (PHQ-9), and the 7-item screen of the Postpartum Depression Screening Scale (PDSS)--for identifying women with postpartum depression in the first 6 months after delivery.

We administered the three instruments via telephone to women who were > or =18 years and had delivered infants 6-8 weeks earlier. We arranged home interviews to confirm DSM-IV criteria current major depressive disorder (MDD) in women who had an above-threshold score on any of the instruments. For women who screened negative on the 6-8 week call, we repeated the screening at 3 months and 6 months to identify emergent symptoms. The primary outcome measures were the screening scores and DSM-IV diagnoses.

Of 135 women reached, 123 (91%) were screened, 29 (24%) had home visits, and 13 (11%) had an MDD within 6 months of delivery. Analyses of the scores at 6-8 weeks postpartum and the DSM-IV diagnoses indicated the EPDS at a cutoff point of > or =10 identified 8 (62%) of cases, the PHQ-9 at a cutoff point of > or =10 identified 4 (31%), and the PDSS 7-item Short Form (PDSS_SF) at a cutoff point of > or =14 identified 12 (92%). However, 15 of 16 (94%) women without current MDD screened positive on the PDSS_SF. The EPDS was significantly more accurate (p = 0.01) than the PDSS_SF and PHQ-9 with the cutoff points used. After correcting for verification bias, we found the EPDS and the PDSS_SF were significantly more accurate than the PHQ-9 (p < 0.03).

Administering the EPDS by phone at 6-8 weeks postpartum is an efficient and accurate way to identify women at high risk for postpartum depression within the first 6 months after delivery.