Circulating Lipids are Associated with PTSD Severity and Predict Symptomatic PTSD in a Cohort of Veterans and Service Members

Post-traumatic stress disorder (PTSD) is characterized by chronic stress, alterations in mood, and avoidance after a traumatic event has occurred. While recovery can occur, many PTSD patients suffer life-long impairments. In combat veterans, high rates of PTSD contribute to increased rates of depression and anxiety and a higher likelihood of suicidal ideation. The lack of biological markers for psychiatric conditions such as PTSD highlights the need for omics-based approaches to diagnosis. Discovery of novel blood-based biomarkers could aid in the development of treatments or therapies, quantify groups for those at the highest risk of adverse events, and provide insight into the molecular underpinnings of PTSD. This study used untargeted lipidomics to analyze 602 circulating lipid species in blood from a cohort of 133 veterans and combat members with varying severities of PTSD. We discovered five circulating lipids, including serum total cholesterol, cholesterol ether (ChE(18:2)), and lipids associated with metabolic dysfunction (cardiolipin : CL(87:7), monolysocardiolipin : MLCL(50:4), and phosphatidylethanolamine plasmalogen/ether lipid : PE(18:1e_20:3)) that correlated significantly with increasing PTSD severity after adjustment for multiple comparisons. Additionally, we showed that symptomatic PTSD patients could be separated from asymptomatic controls using these lipid species. This study contributes to the limited research surrounding the role of circulating lipids in PTSD.