The changes of CVBOLD in MDD patients after ECT compared to before treatment were negatively correlated with the receptor/transporter densities of serotonin (5-HT1A: R = −0.36, pspin = 0.0058; 5HT1B: R = −0.38, pspin = 0.0070; 5HT2A: R = −0.40, pspin = 0.0032; 5HTT: R = −0.33, pspin = 0.0071) and dopamine (D2: R = −0.36, pspin = 0.0054)(Fig. 5). This evidence concerns the gene HTR2A and major depressive disorder.