madman
Super Moderator
4.1. Conclusion
The present study demonstrates a significant interaction effect between testosterone and cortisol for hippocampal volume and a composite measure of episodic memory in men. The nature of the interaction was such that when cortisol was elevated, higher testosterone levels were associated with larger hippocampal volume and better memory performance. This would suggest that in the potentially neurotoxic hormonal milieu associated with high cortisol levels, testosterone may be neuroprotective. In contrast, when cortisol levels were low, lower testosterone levels were associated with larger hippocampal volume and better memory. To our knowledge this is the first demonstration of a testosterone-by-cortisol interaction in a structural brain measure and an associated cognitive ability. Overwhelmingly, studies of neuroendocrine associations with brain structure and function have emphasized the effects of individual hormones and have rarely considered the possibility of between-hormone interactions. These results strongly argue in favor of broadening neuroendocrine research to consider the simultaneous and interactive effects of multiple hormones, the broader hormonal milieu, on brain structure and function.
The present study demonstrates a significant interaction effect between testosterone and cortisol for hippocampal volume and a composite measure of episodic memory in men. The nature of the interaction was such that when cortisol was elevated, higher testosterone levels were associated with larger hippocampal volume and better memory performance. This would suggest that in the potentially neurotoxic hormonal milieu associated with high cortisol levels, testosterone may be neuroprotective. In contrast, when cortisol levels were low, lower testosterone levels were associated with larger hippocampal volume and better memory. To our knowledge this is the first demonstration of a testosterone-by-cortisol interaction in a structural brain measure and an associated cognitive ability. Overwhelmingly, studies of neuroendocrine associations with brain structure and function have emphasized the effects of individual hormones and have rarely considered the possibility of between-hormone interactions. These results strongly argue in favor of broadening neuroendocrine research to consider the simultaneous and interactive effects of multiple hormones, the broader hormonal milieu, on brain structure and function.
