Hormonal and Gender Influences on Mood Regulation

Within the past 20 years, the putative role of gender and gonadal steroids in mood regulation has been transformed from the staple of stereotype to a critical locus of research in clinical neuroscience. This transformation reflects the impact of explosive advances in molecular endocrinology and basic neuroscience, both of which suggest the myriad and dramatic neuroregulatory effects of gonadal steroids. Although direct isomorphs between basic mechanisms and clinical observations are for the most part absent, our burgeoning knowledge of the cellular and central nervous system effects of gonadal steroids is offering new models for understanding the relevance of gender and gonadal steroids in mood regulation. In this chapter, we review some of the major findings in reproductive neuroscience, emphasize the context dependency of many of these findings, and suggest that similar contextual effects underlie the inability to demonstrate uniform effects of gender or gonadal steroids on mood and behavior. Reproductive hormones have played a central historical role in the development of our understanding of the effects of hormones on brain and behavior. More than 2,000 years ago, Aristotle, in his biological treatise Historia Animalium, observed that castration of immature male birds prevents the development of characteristic male singing and sexual behavior (1). One hundred fifty years ago, Berthold (2) successfully transplanted testes in castrated roosters and reversed their hypogonadal symptoms, demonstrating that reproductive organs possess factors that can dramatically alter physiology and behavior. These observations culminated in the claims by nineteenth century organotherapists (e.g.,