Postnatal depressive symptoms among Pacific mothers in Auckland: prevalence and risk factors

To assess the prevalence of and risk factors for postnatal depressive symptoms in a cohort of mothers of Pacific Island infants in Auckland, New Zealand.

The data were gathered as part of the Pacific Island Families Study, in which 1376 mothers were interviewed when their babies were 6 weeks old. The interview included the Edinburgh Postnatal Depression Scale (EPDS).

16.4% of mothers were assessed as probably experiencing depression. Prevalence rates varied from 7.6% for Samoans to 30.9% for Tongans. In addition to ethnicity, risk factors identified by stepwise multiple logistic regression included low Pacific Island acculturation, first birth, stress due to insufficient food, household income less than dollar 40,000, difficulty with transport, dissatisfaction with pregnancy, birth experience, baby's sleep patterns, partner relationship and home. A large prevalence difference between Tongans and other groups remained when the effects of other risk factors were controlled statistically.

The prevalence of depressive symptoms among Pacific mothers is at the upper end of the range typically reported. Focus on the overall rate, however, obscures substantial variation between groups. Risk factors are generally similar to those identified in previous research.

The findings have implications for prevention and treatment and caution against assuming homogeneity within ethnic categories. Further research is required to explain differences in prevalence between Tongan and other Pacific Island groups.