The cross-disorder risk gene CACNA1C is strongly implicated in multiple neuropsychiatric disorders, including autism spectrum disorder (ASD), bipolar disorder (BPD) and schizophrenia (SCZ) (Ferreira et al., 2008; Green et al., 2010; Nyegaard et al., 2010; Splawski et al., 2004). This evidence concerns the gene CACNA1C and bipolar disorder.