Estimates for the smaller group of mothers who had
shown signs of depression during pregnancy were less
precise, but differed from the estimates for non-depressed
women in two important ways. The protective effects of
breastfeeding as planned were smaller for women who had
been depressed during pregnancy; but exclusive breastfeeding
for 4 weeks appeared to exercise a protective effect
for this group, which it did not do for the women who had
not been depressed in pregnancy.