Structure of depressive symptoms in pregnancy and the postpartum period.

BACKGROUND The present study investigated the structure of depressive symptoms in the perinatal period. METHOD The Zung Self-Rating Depression Scale (SDS) was administered to a total of 1329 women in early, middle and late pregnancy and 5 days, 1 month, 6 months, 12 months and 18 months after the delivery. RESULTS A number of somatic items and the suicidal ideation item of the SDS made low contributions to the evaluation of the severity of depression, and as a consequence these were excluded in the principal component analysis. Three factors were interpretable as "Cognitive", "Affective insomnia" and "Attentional" emerged at all eight assessment points. The goodness-of-fit index (GFI) generated by confirmatory factor analyses (LISREL 7.20) proved sufficiently high on all eight occasions. LIMITATION The present study investigated only one self-rating scale and the sample comprised Japanese mothers only. CONCLUSION The three-factor model of the SDS in the perinatal period was derived from exploratory and confirmatory factor analyses. It is noteworthy that the same three-factor structure emerged at all eight collection points in the present study.