The 5-HTTLPR Long, not Short, Allele Predicts Two-year Longitudinal Increases in Cortisol and Declines in Verbal Memory in Older Adults.

Abstract

OBJECTIVES: The short form or s-allele variant of the serotonin transporter polymorphism (5-HTTLPR), as compared with the long form or l-allele variant, has been associated with the presence of cognitive dysfunction, and particularly memory impairment in older adults. This body of cross-sectional work has culminated in the hypothesis that presence of the s-allele predicts greater memory decline in older adults (1). Yet, to date, there are no longitudinal studies which have investigated this issue.METHODS/DESIGN: Here we examine 109 community-dwelling older adults (mean and SD of age=70.7±8.7years) who underwent blood draw for genotyping, cognitive, and psychological testing at baseline, 12-month, and 24-month follow-up.RESULTS: Multilevel modeling found that s-allele carriers (ss or ls) performed worse than ll homozygotes at baseline on delayed verbal recall. Yet, s-allele carriers' memory performance was stable over the two-year follow-up period, while l-allele homozygotes experienced significant memory decline. l-allele homozygote status was associated with both increased cortisol and decreased memory over time, resulting in attenuated verbal memory performance differences compared to s-allele carriers with age.CONCLUSIONS: Overall, our findings do not support the hypothesis that presence of the 5-HTTLPR s-allele is a marker for memory decline in older adults. This article is protected by copyright. All rights reserved.

View details for DOI 10.1002/gps.5319

View details for PubMedID 32400901