We hypothesize that alterations in the serum levels of SUMO1, MDA, CX3CL1, and UCHL1 are associated with the severity of dysthymic symptoms in individuals with a history of PTSD, reflecting the involvement of oxidative stress, neuroinflammatory, and proteostatic mechanisms in affective dysregulation. Here, CX3CL1 is linked to post-traumatic stress disorder.