Depression and telomere length: A meta-analysis

Abstract Background Several recent studies have investigated the relationship between telomere length and depression with inconsistent results. This meta-analysis examined whether telomere length and depression are associated and explored factors that might affect this association. Methods Studies measuring telomere length in subjects with clinically significant unipolar depression were included. A comprehensive search strategy identified studies in PubMed, MEDLINE, PsycINFO, Global Health, The Cochrane Library, and Web of Science. A structured data abstraction form was used and studies were appraised for inclusion or exclusion using a priori conditions. Analyses were conducted using standardized mean differences in a continuous random effects model. Results Thirty-eight studies ( N =34,347) met the inclusion criteria. The association between depression and telomere length was significant, with a Cohen's d effect size of −0.205 ( p