TSPO and post-traumatic stress disorder: The aim of the current study was to test whether higher TSPO binding in the fronto-limbic neurocircuitry, implicated in stress and emotional regulation, occurs in occupation-related PTSD by employing the fluorine F 18–labeled radiotracer [18F]FEPPA (N-(2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide).