The BDNF Val66Met polymorphism moderates the effect of cognitive reserve on 36-month cognitive change in healthy older adults

INTRODUCTION Cognitive reserve (CR) and BDNF Val66Met are independently associated with the rate of cognitive decline in preclinical Alzheimer's disease. This study was designed to investigate the interactive effects of these variables on 36-month cognitive change in cognitively intact older adults. METHODS Data for this investigation were obtained from 445 community-residing participants of the Tasmanian Healthy Brain Project, who underwent genetic screening and annual assessment of neuropsychological, health, and psychosocial function. RESULTS Our main result was that BDNF Val66Met moderated the relationship between baseline CR and change in executive function performance, in that CR-related differences in function decreased across the follow-up period in BDNF Val homozygotes, but became more pronounced in BDNF Met carriers. Similar effects were not observed within the other memory- and language-related cognitive domains. DISCUSSION Inheritance of BDNF Met may be associated with a detrimental influence on the relationship between CR and cognitive change in cognitively intact older adults, but this effect may be restricted to the executive function domain.