There are three main elements you need to understand in how to prove PTSD to VA: Diagnosis In-service stressors Medical “nexus” or link between your PTSD and the in service stressors. https://hadit.com/va-compensation-for-ptsd-and-other-mental-disorders-hill-ponton-p-a/ https://www.hadit.com/proving-a-non-combat-stressor-in-a-va-ptsd-disability-claim-2/ https://hadit.com/dsm-5-criteria-for-ptsd/