PBMC telomerase activity in depression and the response to electroconvulsive therapy

Telomerase, the DNA polymerase responsible for maintaining telomere length, has previously been implicated in depression and the response to antidepressant drugs. In this study, we aimed to compare telomerase activity in peripheral blood mononuclear cells between patients with severe depression recruited as part of the KEEP-WELL Trial (Ketamine for Depression Relapse Prevention Following ECT; NCT02414932) and age- and sex-matched healthy volunteers both at baseline/pre-ECT and at follow-up 1 month later for controls or in patients after a course of ECT. We found no differences in telomerase activity between patients with depression (n = 20) compared to healthy controls (n = 33) at baseline/pre-ECT, or between patients treated with ECT compared to controls at follow-up. In patients, telomerase activity was not associated with mood, as assessed by the 24-item Hamilton Rating Scale for Depression, or the duration of the current depressive episode. Additionally, we found no significant relationship between telomerase activity and exposure to recent or childhood adversity in either the patient or control groups. Overall, our results suggest that telomerase activity is not associated with depression, the therapeutic response to ECT, or exposure to adversity.