There was a trend towards higher TSPO binding in MDD versus HC (sgPFC: Cohen’s d = 0.64, p = .038, 95% CI 0.04–1.24; ACC: d = 0.60, p = .049, 95% CI 0.001–1.21), though these comparisons missed the corrected significance threshold (α = .025) (see Fig. 1, Additional file 1: Table S1). Here, TSPO is linked to major depressive disorder.