Moreover, MAOA hypomethylation has been observed to be predictive of response to pharmacological treatment in MDD (Domschke et al. 2012) and to be modifiable by psychotherapeutic interventions in anxiety disorders (Ziegler et al. 2016; Schiele and Domschke 2018; Schiele et al. 2018; for review see Schiele et al. 2020). This evidence concerns the gene MAOA and major depressive disorder.