SMPD1 and major depressive disorder: Desipramine is a tricyclic amine anti-depression drug that acts as a functional inhibitor of ASM, and the drug blocks the interaction of ASM with membrane inside the lysosomes and causes ASM degradation (Albouz et al., 1981; Jaffrézou et al., 1995; Jenkins et al., 2011; Zhu et al., 2016).