A new study suggests that testosterone may boost overall brain power and cognitive performance. It was also found that the decline of testosterone was connected to the decline of mental functions. This decline in brain performance leads to a slower ability to learn, poor memory, and to such mental states as dementia. The study also suggested that too much testosterone was harmful to the body as well, and that testosterone therapy should only be used for those with existing cognitive problems.
Higher testosterone levels in midlife have been linked to better preservation of tissue in some parts of the brain. And in older men, higher testosterone levels have been associated with better performance on cognitive tests.