Biological Markers for Post-Traumatic Stress Disorder

PTSD affects a major fraction of military combatants and is also very common in the general population. Like other psychiatric conditions, the diagnosis of PTSD is currently based on an interview and questionnaires. However, the validity of these tools is limited since it depends on the evaluator's skills, and on patient compliance and mental status; and may be prone to exaggeration or minimization of symptoms. This prompts an urgent need for evaluation that will combine biomarkers for objective diagnosis, and follow up of individuals with PTSD. Knowledge has grown in recent years regarding the biologic pathophysiological cascade responsible for the development of a "non-healing wound in the brain" that characterizes PTSD. Shortly after the traumatic experience, fundamental changes in autonomic nervous and endocrine activity are evident, together with changes in brain function; these can become chronic in those with long-standing unremitting PTSD. Several studies indicate good correlations of the diagnosis and severity of PTSD, with objective biological measures such as heart rate variability (HRV), brain connectivity and endocrine activity. However, the currently available data on these biological variables are still not sufficient to be used for diagnosis of PTSD. The aim of the current study is to characterize the biological fingerprint of PTSD, by using a combination of biological measures, for an objective diagnosis.