The association between endogenous free testosterone and cognitive performance: a population-based study in 35 to 90 year-old men and women.

The relationship between testosterone (T) and cognition has yielded conflicting evidence, showing both positive and negative influences of T on cognitive performance. The association between free testosterone (FT) and cognition was revisited in a large population-based sample of 1276 women and 1107 men (35-90 years of age), assessed individually on visuospatial, verbal fluency, semantic, and episodic memory tasks. For men, higher FT levels were associated with better visuospatial abilities, semantic memory, and episodic memory, with greater positive influence with increasing age. Statistical covariates included age, education, and select medications. For women, FT was negatively associated with verbal fluency, semantic memory, and episodic memory, although only verbal fluency was significant at conventional alpha levels. These results support the claim that FT exerts sex-specific influences on cognitive performance.