Telomere length and cortisol reactivity in children of depressed mothers

Abstract

A growing body of research demonstrates that individuals diagnosed with major depressive disorder (MDD) are characterized by shortened telomere length, which has been posited to underlie the association between depression and increased instances of medical illness. The temporal nature of the relation between MDD and shortened telomere length, however, is not clear. Importantly, both MDD and telomere length have been associated independently with high levels of stress, implicating dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and anomalous levels of cortisol secretion in this relation. Despite these associations, no study has assessed telomere length or its relation with HPA-axis activity in individuals at risk for depression, before the onset of disorder. In the present study, we assessed cortisol levels in response to a laboratory stressor and telomere length in 97 healthy young daughters of mothers either with recurrent episodes of depression (i.e., daughters at familial risk for depression) or with no history of psychopathology. We found that daughters of depressed mothers had shorter telomeres than did daughters of never-depressed mothers and, further, that shorter telomeres were associated with greater cortisol reactivity to stress. This study is the first to demonstrate that children at familial risk of developing MDD are characterized by accelerated biological aging, operationalized as shortened telomere length, before they had experienced an onset of depression; this may predispose them to develop not only MDD but also other age-related medical illnesses. It is critical, therefore, that we attempt to identify and distinguish genetic and environmental mechanisms that contribute to telomere shortening.

Delay discounting, genetic sensitivity, and leukocyte telomere length

“…When the sample in this study is stratified by sex, the association between delay discounting and LTL is observed in females but not in males. Our findings are in agreement with earlier evidence that females are more sensitive to social adversity and stress (28,29,63) with respect to cellular aging. Overall, shortened LTL mirrors the cell's mitotic history and replicative history of hematopoietic stem cells, and is further subjected to the effects of inflammation and oxidation (36,37,64).…”

Mechanisms of Stress in Humans

“…Four saliva samples were collected throughout these tasks to obtain cortisol levels. Among other findings, the results have shown that shorter telomeres were associated with higher cortisol reactivity, not to basal level of cortisol, suggested a vulnerability to develop illnesses later, such as major depressive disorder (Gotlib et al, 2015).…”

“…According to a study conducted by Gotlib et al (2015), a shortened telomere is a risk factor for developing major depressive disorder. The researchers recruited ninety-seven 10-to 14-year-old girls, who had not experienced psychological disorders, to participate in the study.…”

Analyzing leukocyte telomere length in bipolar disorder

“…For instance, Gotlib et al showed that children at familial risk of developing major depressive disorder (MDD) had shorter LTL compared to controls, even before manifesting an onset of depression. 3 Michalek et al analyzed genetic polymorphisms of telomerase components (TERT and TERC) as predictors of LTL to demonstrate that shortened telomeres might increase risk for early-onset recurrent MDD in a large sample of cases and controls. 4 In this context, shortened TL was considered as a susceptibility marker for MDD that is present before illness onset.…”