An association of common CDH13 variation with neurodevelopmental and psychiatric disorders, particularly ADHD (Lasky-Su et al., 2008; Lesch et al., 2008; Neale et al., 2008, 2010; Uhl et al., 2008a,b; Zhou et al., 2008; Treutlein et al., 2009; Lionel et al., 2011) and comorbid conditions, was reported. This evidence concerns the gene CDH13 and attention deficit-hyperactivity disorder.