BRD2 and major depressive disorder: We found that the changes of BEN in MDD patients after ECT compared to before treatment were positively correlated with the receptor/transporter densities of serotonin (5‐HT1B: r = 0.4; 5‐HT2A: r = 0.41) and norepinephrine (NAT: r = 0.12) (Figure 6A).