Depressive and Anxiety Disorders Showing Robust, but Non-Dynamic, 6-Year Longitudinal Association With Short Leukocyte Telomere Length.

OBJECTIVE: Several cross-sectional studies have related depressive and anxiety disorders to shorter leukocyte telomere length (LTL) as an indicator of cellular aging. However, these studies have left many unresolved questions about underlying causality and ordering of associations. The objective of the present large, longitudinal study was to examine the relationship between depressive and anxiety disorders and LTL over a 6-year time period.
METHOD: Data are from the Netherlands Study of Depression and Anxiety, including 2,292 patients with remitted and current diagnoses of depressive or anxiety disorders and 644 healthy control subjects. LTL was assessed using quantitative PCR and measured at baseline and after 6 years; depressive and anxiety disorder diagnoses and characteristics (course, duration, and severity) were determined at baseline and after 2, 4, and 6 years.
RESULTS: Results showed that persons with remitted (B=-52.6) and current (B=-60.8) depressive or anxiety disorder had consistently shorter LTL compared with healthy control subjects across baseline and at the 6-year follow-up, remaining significant when controlling for lifestyle and somatic health variables. Changes in the course of depressive or anxiety disorder characteristics over 6 years, however, were not associated with different LTL attrition rates.
CONCLUSIONS: This study confirmed robust associations of depressive and anxiety disorders with shorter telomeres, but interestingly, it did not demonstrate that depressive and anxiety disorders and LTL change together over time, suggesting the absence of a direct within-person relationship. Short LTL is suggested to be either a long-term consequence or an underlying vulnerability factor for depressive or anxiety disorders.