Measuring Change in Postpartum Depression Risk among Women who Received Interpersonal Psychotherapy
Our study evaluated the efficacy of interpersonal psychotherapy on women at-risk of postpartum depression (PPD). The Edinburgh Postnatal Depression Scale (EPDS) was administered both to screen for eligibility and at post-intervention. Interpersonal psychotherapy significantly reduced PPD risk (p = .05).
The EPDS was developed by Cox, Holden and Sagovsky (1987) who modified 21 items from the Irritability, Depression and Anxiety Scale and the Hospital Anxiety and Depression Scale and constructed the remaining items. The tool was then administered to women know to have depression and non-depressed women in order to measure criterion validity (concurrent) and split half-reliability (Cox, Holden & Sagovsky, 1987). The authors concluded that the tool is valid and reliable, with a score of 13 and above indicating PPD risk.
The authors caution the EPDS is designed to identify depressive symptoms within the last 7 days and is not a diagnostic tool. A clinical assessment is required to confirm a PPD diagnosis as the DSM stipulates that symptoms must be present for 2 weeks (Cox, Holden & Sagovsky, 1987). This caveat is relevant to the validity of our findings as it is possible that administering the EPDS once at post-test may have measured sub-clinical depression risk rather than PPD risk. Matthey and Ross-Hamid (2012) recommend that studies using the EPDS repeat its administration for increased validity, however this suggestion was not adopted in our study. It is possible that this limitation decreased the power of our study and may explain why our findings did not reach greater significance.
Cox J.L., Holden J.M., & Sagovsky R. (1987). Detection of postnatal depression. Development of the 10-item Edinburgh Postnatal Depression Scale. British Journal of Psychiatry, 150, 782–786.
Matthey, S. & Ross-Hamid, C. (2012). Repeat testing on the Edinburgh Depression Scale and the HADS-A in pregnancy: Differentiating between transient and enduring distress. Journal of affective disorders, 141(2), 213-221.