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Free keywords:
POSTTRAUMATIC-STRESS-DISORDER; CONNOR-DAVIDSON RESILIENCE; SCALE
CD-RISC; PSYCHIATRIC-DISORDERS; ALLOSTATIC LOAD; EPIGENETIC AGE;
GENE-EXPRESSION; LIFE-STYLE; SYMPTOMS; TRAUMANeurosciences & Neurology; Epigenetic aging; Biomarkers; Veterans; Stress; PTSD; Resilience;
Abstract:
Accelerated epigenetic aging, the difference between the DNA methylation-predicted age (DNAm age) and the chronological age, is associated with a myriad of diseases. This study investigates the relationship between epigenetic aging and risk and protective factors of PTSD. Genome-wide DNA methylation analysis was performed in 211 individuals including combat-exposed Australian veterans (discovery cohort, n=96 males) and trauma-exposed civilian males from the Grady Trauma Project (replication cohort, n=115 males). Primary measures included the Clinician Administered PTSD Scale for DSM-5 and the Connor-Davidson Resilience Scale (CD-RISC). DNAm age prediction was performed using the validated epigenetic clock calculator. Veterans with PTSD had increased PTSD symptom severity (P-value=3.75x10(-34)) and lower CD-RISC scores (Pvalue=7.5x10(-8)) than veterans without PTSD. DNAm age was significantly correlated with the chronological age (P-value=3.3x10(-6)), but DNAm age acceleration was not different between the PTSD and non-PTSD groups (P-value=0.24). Evaluating potential protective factors, we found that DNAm age acceleration was significantly associated with CD-RISC resilience scores in veterans with PTSD, these results remained significant after multiple testing correction (P-value=0.023; r=0.32). This finding was also replicated in an independent trauma-exposed civilian cohort (P-value=0.02; r=0.23). Post-hoc factor analyses revealed that this association was likely driven by "self-efficacy" items within the CD-RISC (P-value=0.015; r=0.35). These results suggest that among individuals already suffering from PTSD, some aspects of increased resilience might come at a biological cost.
