A single nucleotide polymorphism (SNP) rs1006737 in CACNA1C, implicated in bipolar disorder (Ferreira et al. 2008) and other neuropsychiatric disorders (Gargus 2006, 2009), has been found to increase brain volumes, particularly grey matter volumes (Kempton et al. 2009), and impair appropriate functioning of fronto-temporal circuits (Wang et al. 2011) important for emotional processing (Radua et al. 2012). Here, CACNA1C is linked to bipolar disorder.