TY - JOUR T1 - Effects of Recent Stress and Variation in the Serotonin Transporter Polymorphism (5-HTTLPR) on Depressive Symptoms: A Repeated-Measures Study of Adults Age 50 and Older. JF - Behavior Genetics Y1 - 2016 A1 - Thalida E. Arpawong A1 - Jinkook Lee A1 - Drystan F. Phillips A1 - Eileen M. Crimmins A1 - Morgan E. Levine A1 - Carol A Prescott KW - Aged KW - Alleles KW - depression KW - Depressive Disorder KW - Ethnic Groups KW - Female KW - Gene-Environment Interaction KW - Genetic Association Studies KW - Genetic Predisposition to Disease KW - Haplotypes KW - Humans KW - Life Change Events KW - Male KW - Middle Aged KW - Polymorphism, Single Nucleotide KW - Promoter Regions, Genetic KW - Serotonin Plasma Membrane Transport Proteins KW - Stress, Psychological AB -

Depending on genetic sensitivity to it, stress may affect depressive symptomatology differentially. Applying the stress-diathesis hypothesis to older adults, we postulate: (1) recent stress will associate with increased depressive symptom levels and (2) this effect will be greater for individuals with at least one short allele of the serotonin transporter gene promoter region (5-HTTLPR). Further, we employ a design that addresses specific limitations of many prior studies that have examined the 5-HTTLPR × SLE relation, by: (a) using a within-person repeated-measures design to address fluctuations that occur within individuals over time, increase power for detecting G × E, and address GE correlation; (b) studying reports of exogenous stressful events (those unlikely to be caused by depression) to help rule out reverse causation and negativity bias, and in order to assess stressors that are more etiologically relevant to depressive symptomatology in older adults. The sample is drawn from the Health and Retirement Study, a U.S. population-based study of older individuals (N = 28,248; mean age = 67.5; 57.3 % female; 80.7 % Non-Hispanic White, 14.9 % Hispanic/Latino, 4.5 % African American; genetic subsample = 12,332), from whom measures of depressive symptoms and exogenous stressors were collected biannually (1994-2010). Variation in the 5-HTTLPR was characterized via haplotype, using two single nucleotide polymorphisms (SNPs). Ordered logit models were constructed to predict levels of depressive symptoms from 5-HTTLPR and stressors, comparing results of the most commonly applied statistical approaches (i.e., comparing allelic and genotypic models, and continuous and categorical predictors) used in the literature. All models were stratified by race/ethnicity. Overall, results show a main effect of recent stress for all ethnic groups, and mixed results for the variation in 5-HTTLPR × stress interaction, contingent upon statistical model used. Findings suggest there may be a differential effect of stressors and 5-HTTLPR on depressive symptoms by ethnicity, but further research is needed, particularly when using a haplotype to characterize variation in 5-HTTLPR in population-based sample with a diverse ethnic composition.

PB - 46 VL - 46 IS - 1 U2 - PMC4720538 U4 - 5-HTTLPR/Depressive symptoms/G/Older adults/Race differences/Stressful life events/Genetic analysis ER -