Depressive Symptoms and Salivary Telomere Length in a Probability Sample of Middle-Aged and Older Adults

Objective: To examine the association between depressive symptoms and salivary telomere length in a probability sample of middle-aged and older adults, and to evaluate age and sex as potential moderators of this association and test whether this association was incremental to potential confounds. Methods: Participants were 3,609 individuals from the 2008 wave of the Health and Retirement Study. Telomere length assays were performed using quantitative real-time polymerase chain reaction on DNA extracted from saliva samples. Depressive symptoms were assessed via interview, and health and lifestyle factors, traumatic life events, and neuroticism were assessed via self-report. Regression analyses were conducted to examine the associations between predictor variables and salivary telomere length. Results: After adjusting for demographics, depressive symptoms were negatively associated with salivary telomere length (b=-.003; p=.014). Furthermore, this association was moderated by sex (b=.005; p=.011), such that depressive symptoms were significantly and negatively associated with salivary telomere length for men (b=-.006; p<.001) but not for women (b=-.001; p=.644). The negative association between depressive symptoms and salivary telomere length in men remained statistically significant after additionally adjusting for cigarette smoking, body mass index, chronic health conditions, childhood and lifetime exposure to traumatic life events, and neuroticism. Conclusions: Higher levels of depressive symptoms were associated with shorter salivary telomeres in men, and this association was incremental to several potential confounds. Shortened telomeres may help account for the association between depression and poor physical health and mortality.