Mood disturbances have been identified in association with changes in levels of reproductive hormones. The use of hormonal measures in the diagnosis of reproductive endocrine-related mood disorders is highly variable, ranging from necessary in perimenopausal depression to irrelevant in premenstrual syndrome. This article describes our view of the use of hormonal measures for diagnostic and research purposes in perimenopausal depression and premenstrual syndrome. We suggest that the understanding of these disorders lies in as yet unidentified contextual factors rather than in hormonal excesses or deficiencies.