Background: Postnatal depression occurs in 10-15% of Western women. In Japan, there is a traditional support system for perinatal women and there have been few prospective studies on postnatal depression in terms of cross-cultural studies.
Methods: First, a cross-cultural study on postnatal depression was performed. Ninety-eight Japanese women living in England and 88 Japanese women living in Japan were recruited and followed up to 3 months postnatally. The Edinburgh Postnatal Depression Scale (EPDS) and Schedule for Affective Disorder and Schizophrenia were used as a self-report questionnaire and psychiatric diagnostic interview. Diagnoses of depression were made by Research Diagnostic Criteria. Second, a study on 'Satogaeri bunben' (a traditional ritual (support system) for perinatal women in Japan; 'Satogaeri' means returning to the original family town or house and 'bunben' means delivery) was undertaken. Seventy-five mothers were asked to answer the questionnaire 6 months postnatally. The questionnaire was devised by the authors about the choice of Satogaeri bunben and the reasons for the decision.
Results: The incidence of postnatal depression was 12 and 17% in the English and Japanese groups of mothers, respectively. However, subjects from both groups supressed expression of their depressed mood in answering the EPDS. Satogaeri bunben itself did not lower the incidence of postnatal depression. In the study on Satogaeri bunben, 23 of 75 women did not choose Satogaeri bunben; moreover, seven of these women did not have good support from their own mothers.
Discussion: Having found that postnatal depression is not uncommon in Japanese women, a screening system should be developed, in particular because Japanese women would not naturally express their emotions, and Satogaeri bunben needs to be reconsidered qualitatively.