Cholesterol and serotonin transporter polymorphism interactions in late-life depression

Background: It has been suggested that the functional polymorphism in the serotonin transporter gene linked promoter region (5-HTTLPR) modifies associations between vascular diseases (coronary artery syndrome or stroke) and depression. This study investigated whether the 5-HTTLPR polymorphism has modifying effects on previously identified associations between cholesterol levels and prevalence/incidence of late-life depression. Methods: In 732 community residents aged 65+, depression was ascertained (Geriatric Mental State Schedule) at baseline and after 2 years. 5-HTTLPR genotype and lipid levels (total, HDL and LDL cholesterol and triglycerides) were assayed. Covariates were age, sex, education, disability, and cognitive function. Results: Significant associations between lower baseline HDL cholesterol levels with prevalent and incident depression were also modified by 5-HTTLPR polymorphism, and were only significant in the presence of one or more copies of the s allele. Conclusion: A more atherogenic lipid profile, as indicated by lower HDL cholesterol is a risk factor for late-fife depression and this risk is modified by a gene implicated in serotonin transport. (C) 2009 Elsevier Inc. All rights reserved.