Cholesterol and serotonin transporter polymorphism interactions in late-life depression.

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.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.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.A more atherogenic lipid profile, as indicated by lower HDL cholesterol is a risk factor for late-life depression and this risk is modified by a gene implicated in serotonin transport.