Biomarkers of neurodegeneration in post-traumatic stress disorder: an integrative review

Abstract

Post-traumatic stress disorder (PTSD) is a chronic psychiatric disorder that occurs following exposure to traumatic events. The prevalence of PTSD is estimated to be 5-10% worldwide, and it is associated with significant distress and disability. Recent evidence suggests that PTSD may be a risk factor for the development of subsequent neurodegenerative disorders, including Alzheimer’s dementia and Parkinson’s disease. Identification of biomarkers known to be associated with neurodegeneration in patients with PTSD would shed light on the pathophysiological mechanisms linking these disorders, and would also help in the development of preventive approaches aimed at reducing the risk of neurodegenerative disorders in PTSD. In the current review, the PubMed and Scopus databases were searched for studies aimed at identifying genetic, biochemical, neuroimaging or behavioral markers associated with neurodegeneration in patients with PTSD. Out of a total of 342 citations retrieved, 29 relevant studies were identified for inclusion in the review. The results of these studies suggest that several potentially relevant biological markers, including cerebral cortical thinning, disrupted white matter integrity, specific genetic polymorphisms, immune-inflammatory alterations, vitamin D deficiency, metabolic syndrome and parasomnias, may be associated with an increased risk of neurodegeneration in patients with PTSD. Though many of these results need replication, they highlight a number of biological pathways that plausibly link PTSD with neurodegenerative disorders, and suggest potentially valuable avenues for prevention and early intervention in this patient population.