ABSTRACT
Androgens and their effects on behavior have been an area of study for over a century. In 1889, Dr. BrownSequard injected himself with an extract from crushed animal testicles, reporting that this treatment gave him increased energy, muscular strength, stamina, and mental agility (1). Although crude, this approach led the way to the discovery of androgens. Since then, the focus of most androgen research has been in the area of reproductive function. More recently, the focus of attention has turned to hormone effects on the central nervous system (CNS) and the process of aging, with particular emphasis on the potential antiaging effects of hormone replacement therapy. This chapter will explore the complex relationship between androgens and cognition. First, mechanisms by which hormones exert their effects in the CNS will be described, including organizational and activational effects. Next, the relationship between androgens and cognition in humans will be examined, including endogenous levels as well as studies on hormone manipulation in healthy young and older populations. Finally, the relationship between androgens and cognition will be considered with respect to the endocrine disorders that result in excessive or insufficient hormone levels. This chapter will feature cognition, rather than human behavioral characteristics such as mood or emotion. Readers may refer to Ref. (2) for a review of the relationship between androgens and mood or behavior.
