INS and depressive disorder: INS is thought to play a central role for one's emotional processing (Iaria et al., 2008; Lamm and Singer, 2010) and is involved in various neuropsychiatric diseases such as mood disorders, depressive disorders, and panic disorders (Paulus and Stein, 2006; Nagai et al., 2007; Fitzgerald et al., 2008; Liu et al., 2010; Guo et al., 2011).