TY - JOUR T1 - Alterations of cellular aging markers in obsessive–compulsive disorder: mitochondrial DNA copy number and telomere length JF - Journal of Psychiatry and Neuroscience JO - JPN SP - E451 LP - E458 DO - 10.1503/jpn.200238 VL - 46 IS - 4 AU - Jee In Kang AU - Chun Il Park AU - Jue Lin AU - Shin Tae Kim AU - Hae Won Kim AU - Se Joo Kim Y1 - 2021/07/01 UR - http://jpn.ca/content/46/4/E451.abstract N2 - Background: The present study examined whether mitochondrial DNA copy number (mtDNAcn) and telomere length — key markers of cellular aging — were altered in male and female participants with obsessive–compulsive disorder (OCD) compared to healthy controls. We also tested for associations between these alterations and OCD-related clinical features and inflammatory index.Methods: A total of 235 patients with OCD (38.7% female) and 234 healthy controls (41.5% female) were included. We quantified whole-blood mtDNAcn and leukocyte telomere length using quantitative polymerase chain reaction. We also calculated the neutrophil-to-lymphocyte ratio from complete blood cell counts.Results: Multivariate analysis of covariance showed that OCD status had a significant overall effect on cellular aging markers in men (Wilks λ = 0.889, F2,275 = 17.13, p < 0.001) and women (Wilks λ = 0.742, F2,182 = 31.61, p < 0.001) after controlling for age, body mass index and childhood trauma. In post-hoc comparisons, men with OCD had lower mtDNAcn than controls (p < 0.001), but we found no between-group difference for telomere length (p = 0.55). Women with OCD had a significantly lower mtDNAcn (p < 0.001) and shortened telomere length (p = 0.023) compared to controls. Moreover, the lower mtDNAcn shown in the OCD group was significantly correlated with an increase in systemic inflammation for both sexes, as measured by neutrophil-to-lymphocyte ratio.Limitations: The present cross-sectional design did not allow us to infer a causal relationship between OCD disease status and cellular aging markers.Conclusion: The present study is, to our knowledge, the first to demonstrate alterations in mtDNAcn and telomere shortening in OCD. These results suggest that aging-associated molecular mechanisms may be important in the pathophysiology of OCD. ER -