BackgroundRisk and protective factors for postpartum depression have been extensively studied, and in recent studies an association between breastfeeding and maternal mood has been reported. The present retrospective, cross-sectional study was conducted to evaluate the association between breastfeeding-related variables and postpartum depression (based on Edinburgh Postnatal Depression Scale threshold criteria) within the context of other known risk factors. MethodBreastfeeding information, demographic information, and scores on the Edinburgh Postnatal Depression Scale were examined from the Canadian Maternity Experience Survey. This survey contains data collected from 6421 Canadian mothers between October 2006 and January 2007, and 2848 women between five and seven months postpartum were included in the current analyses. ResultsIn contrast to previous research, logistic regression analyses revealed that when considered within the context of other risk factors, breastfeeding attempt and duration were not associated with postpartum depression at five to seven months postpartum. Although a relationship between the prenatal intention to combination feed and postpartum depression was observed, these variables were no longer related once other potential risk factors were controlled for. Factors that were associated with postpartum depression included lower income, higher perceived stress, lower perceived social support, no history of depression, or no recent history of abuse. LimitationsA clinical diagnostic instrument was not used and variable selection was restricted to data collected as part of this survey. ConclusionThese findings suggest that the association between breastfeeding and postpartum depression reported by previous researchers may in fact be due to alternative risk factors.