A parallel insight comes from a recent paper [64] in treatment-resistant depression: rather than focusing solely on the global state of treatment resistance, the study explicitly recruited patients with a defined mutation in the ANK3 gene, finding that in this subpopulation, the study medication was more effective than placebo in reducing depressive symptoms, despite the failure of the liafensine itself in the non-selected treatment-resistant depression population. Here, ANK3 is linked to depressive disorder.