MMP2 and post-traumatic stress disorder: Specifically, the Past PTSD (>5 y) group showed a strong correlation between MMP-2 and GABA (rho = 0.81, Section 2.3, Figure 4), while GABA levels were significantly lower in the Past PTSD (≤5 y) group (median: 54.33 nmol/L, IQR: 43.68–65.87) compared to the controls (median: 406.94 nmol/L, IQR: 259.67–454.33, p < 0.001, Section 2.1, Table 1).