Post-Traumatic Stress Disorder (PTSD) has long been associated with its clinical presentation, ranging from intrusive memories to heightened states of arousal. For clinicians and researchers alike, the ability to identify biological markers indicative of PTSD can revolutionize its diagnosis and treatment. In our recent study, we made a significant breakthrough in this regard, discovering a unique RNA marker present in PTSD patients but undetectable in healthy controls. Background: Over the past few years, there has been a growing interest in exploring the molecular underpinnings of PTSD. Previous research had hinted at potential molecular differences in PTSD patients, but a specific, distinguishing marker remained elusive. Circulating RNAs, which play crucial roles in cellular communication and function, have recently become the focus of many neurological and psychiatric disorder studies. Building on this foundation, our developed a panel to explore the possible connection between circulating RNAs and PTSD. Methods: We recruited two cohorts for our study: one comprising individuals diagnosed with PTSD and the other of age and gender-matched healthy controls. Blood samples were taken from each participant, and a comprehensive RNA sequencing was carried out to identify and quantify circulating RNAs. Findings: Remarkably, we identified a specific RNA marker that was consistently present in the blood samples of PTSD patients. This RNA was, however, undetectable in every sample from the healthy control group. The specificity and sensitivity of this marker were further confirmed through rigorous statistical analyses, showcasing its potential as a reliable biomarker for PTSD. Moreover, the presence of this RNA marker was not influenced by the severity of PTSD symptoms, suggesting its role in the fundamental pathology of the disorder rather than its clinical manifestation. This distinct presence or absence, irrespective of PTSD symptom severity, opens the door to potentially identifying PTSD even in individuals with subclinical or early-stage symptoms. Implications: The discovery of this RNA marker has significant implications for both research and clinical practice: 1. Diagnostic Precision: The presence of this RNA can serve as a robust biological indicator for PTSD, enhancing diagnostic precision and potentially reducing misdiagnoses. 2. Treatment Development: Understanding the role and function of this RNA might pave the way for targeted therapeutic interventions, offering hope for more effective PTSD treatments in the future. 3. Early Detection: As the RNA marker is detectable irrespective of symptom severity, it offers the potential for earlier diagnosis and intervention, which can be pivotal in the management of PTSD. Conclusion: The discovery of an RNA marker exclusive to PTSD patients and its absence in healthy controls is a monumental step forward in the field of PTSD research. While further studies are needed to unravel the exact role of this RNA in PTSD's pathogenesis, its presence provides a tangible biological anchor to a disorder often marred by its subjective diagnostic criteria. With continued research and exploration, we may soon find ourselves equipped with more precise diagnostic tools and, perhaps, novel treatment approaches rooted in molecular science.