Results of protocol # 90-M-0077 demonstrated the therapeutic efficacy of estradiol therapy (ET) in perimenopausal depression, independent of its effects on vasomotor symptoms. Nevertheless, the long term risks of ET to endometrial and breast tissues continue to deter many women from its use. Recently, selective estrogen receptor modulators (SERMs) and phytoestrogens (plant-derived estrogen-like compounds) have become available and are reported to display both tissue-specific profiles of estrogen agonist and antagonist actions and differential affinities for the two forms of estrogen receptor. For many women, these novel compounds would represent a safer alternative to ET for the prevention of osteoporosis and the treatment of menopausal symptoms. However, the effects of SERMs and phytoestrogens on mood and cognitive function in perimenopausal women remain undetermined.