Androgens, ageing, behavior and cognition: Complex interactions and novel areas of inquiry

This article reviews the complex relationship between androgens and behavior, changes that occur with ageing and in particular hormone effects on cognitive abilities. Androgens are steroid hormones that exert both anabolic and androgenic effects which masculinize the developing organism and brain structure. Throughout the lifespan, androgens continue to exert notable effects on behavior and cognition beyond reproductive functions. As men age, they undergo a natural decline in circulating testosterone which can effect muscle mass, bone density, sexual activity and cognition. Neural effects of testosterone mediated through the androgen receptor are widespread and complex but may have specific effects on spatial navigation and memory. In humans, testosterone may underlie gender differences on cognitive tasks with evidence for men outperforming women on spatial tasks. Studies of exogenous testosterone administration in men have yielded mixed results, some demonstrating improvements in spatial tasks and others failing to find improvements. Preliminary results for an ongoing study are included which suggest improvements in spatial and verbal memory in a group of healthy older men from robustly elevated testosterone levels. Overall, the effects of androgens on behavior are complex with numerous modulators producing context dependent interactions and bi-directional interactions as well as effects on cognition.