Concordance and Discordance of the Postpartum Depression Screening Scale and Patient Health Questionnaire-9 in an Ethnically Diverse Sample

ABSTRACT

Postpartum depression is a treatable but crippling mood disorder that can adversely affect new mothers and their children. This secondary analysis compared the ability of the Postpartum Depression Screening Scale (PDSS) and the Patient Health Questionnaire-9 (PHQ-9) to assess depressive symptoms in 80 low-income ethnically diverse mothers. The PDSS specifically measures postpartum depressive symptoms, while the PHQ-9 assesses general depressive symptoms. The data from both instruments had high internal consistency reliability (.97 for the PDSS and .88 for the PHQ-9); overall concordance was 58%. Most of the discordance occurred when the PHQ-9 scores were in the normal or mild depression range, whereas the PDSS scores ranged from minor depression to positive screen for postpartum depression. The need for future research is discussed highlighting the use of a gold standard of a diagnostic interview for major depression so that sensitivity and specificity of the scales can be determined.

KEYWORDS:

• Postpartum depression
• PDSS
• PHQ-9
• race
• ethnicity
• immigrant