This analysis examines correlations between four key biomarkers—glutamine (plasma concentrations), glutathione (antioxidant capacity), caspase-1 (inflammatory status), and brain-derived neurotrophic factor (BDNF; neurotrophic support)—and sleep disturbance domains assessed by the PSQI-A across three groups: individuals with a current PTSD diagnosis lasting ≤ 5 years (PTSD ≤ 5 y, N = 33), those with a current PTSD diagnosis lasting > 5 years (PTSD > 5 y, N = 31), and a control group with no diagnosis of PTSD (No PTSD, N = 28). This evidence concerns the gene BDNF and post-traumatic stress disorder.