SLC8A3 and bipolar disorder: NCX3 is highly expressed in the CNS, and consistent with this, recent GWAS have associated variants in NCX3 with anhedonia and insomnia (Lane et al., 2019; Ward et al., 2019) with suggestive association having been also found for bipolar disorder ( Izard and Vandenbergh, 1982; Stahl et al., 2019).