The role of telomerase reverse transcriptase (TERT) has been widely investigated in the contexts of aging and age-related diseases. Interestingly, decreased telomerase activities (and accelerated telomere shortening) have also been reported in patients with emotion-related disorders, opening the possibility for subjective appraisal of stressful stimuli playing a key role in stress-driven telomere shortening. In fact, patients showing a pessimistic judgment bias have shorter telomeres. However, these evidences in humans are correlational and the causal inference...