CD274 and major depressive disorder: The PD-1/PD-L1 group presented significant reductions in anxiety (HADS-A: mean difference [MD] = - 2.4) and depression (HADS-D: MD = - 2.3) at 6 months (both *p < 0.001), with lower rates of clinically significant anxiety (28.3% vs. 42.1%) and depression (24.3% vs. 38.8%; p < 0.05).