Postnatal psychiatric morbidity: a validation study of the GHQ-12 and the EPDS as screening tools.

Objective: To assess the validity of the 12-Item General Health Questionnaire (GHQ-12) and the Edinburgh Postnatal Depression Scale (EPDS) in screening for the most common postnatal psychiatric morbidities (mood, anxiety and adjustment disorders).
Method: A two-phase cross-sectional study was designed. First, a sample of 1453 women visiting at 6 weeks postpartum completed the GHQ-12 and the EPDS questionnaires. Second, based upon EPDS outcomes, participants were stratified and randomly selected within each stratum for clinical evaluation [Structured Clinical Interview for DSM-IV (SCID)]. Receiver operating characteristic (ROC) analysis was used.
Results: The concurrent validity was satisfactory (0.80). At optimum cut-off scores, both GHQ-12 and EPDS yielded very good sensitivity (80; 85.5) and specificity (80.4; 85.3), respectively. ROC curves showed that the performance of the EPDS (AUC=0.933) is slightly superior to that of GHQ-12 (AUC=0.904).
Conclusion: Both GHQ-12 and EPDS are valid instruments to detect postnatal depression as well as postnatal anxiety and adjustment disorders.