Brain-derived neurotropic factor and cortisol levels negatively predict working memory performance in healthy males

There is now significant literature suggesting that increasing brain-derived neurotropic factor (BDNF) signalling may improve memory-related disorders such as Alzheimer's disease. However, the effects of BDNF on short-term and working memory are not clear and existing evidence is inconsistent. Here we measured plasma BDNF and salivary cortisol levels, as well as working memory, on an N-Back task before and after mixed psychosocial/physiological stress induction in healthy males (N = 29). Stress induction was associated with higher circulating cortisol, but not BDNF levels. Higher cortisol and BDNF levels were significantly associated with poorer accuracy before and after stress induction. There was also a significant interaction, such that higher BDNF was associated with a buffering effect on the negative association between high cortisol and working memory. Future studies should replicate this data in larger samples, with emphasis on cortisol/BDNF interactions in determining working memory performance.