<qa>  What is the need for effective therapies for treating postpartum-related mood disorders?Postpartum-related mood disorders cause significant distress to a potentially large number of women. The demand for effective therapies for treating these mood disorders is considerable, as is the need to define clinical or biologic markers that may predict successful response of these mood disturbances to estradiol. Despite the prevalence of postpartum depressions, only a few double-blind, controlled trials of antidepressant agents have been performed in this condition 1-4- only two of which were placebo-controlled. A recent large multicenter trial failed to confirm the initially promising but anecdotal reports of the protective role of fish oil in PPD 5. Similarly, despite evidence of estradiol s therapeutic efficacy in trials 