Assessing the serum concentration levels of NT-4/5, GPX-1, TNF-α, and l-arginine as biomediators of depression severity in first depressive episode patients with and without posttraumatic stress disorder

l-arginine, TNF-α, NT-4/5 and GPX-1 can be markers of depression severity in both males and females with first depressive episode with or without posttraumatic stress disorder.