CAV2 and attention deficit-hyperactivity disorder: In this review, we will summarize literature on the structure and function of CaV genes, we will briefly overview some of the genetic tools that have allowed researchers to establish genetic links between CaVs and psychiatric disorders, then we will examine studies that have linked CaV genes to several psychiatric disorders including bipolar disorder (BD), schizophrenia (SCZ), autism spectrum disorders (ASD), anxiety disorders, major depressive disorder (MDD), and attention-deficit and hyperactivity disorder (ADHD).