CACNA1C, which encodes for the Cav1.2 α1 subunit of L-type calcium channels (LTCCs), is one of the best-supported risk loci for schizophrenia and bipolar disorder since it harbors variants with consequences on neural processing and connectivity (Gurung and Prata, 2015; Kabir et al., 2017). Here, CACNA1C is linked to bipolar disorder.