CNTN6 and major depressive disorder: Various studies have implicated CNTN6, and more broadly contactins as a group, in metabolic, neurological, and mental health conditions, brain disorders, intellectual disability, depression, and AD-related traits (Jia et al., 2017; Oguro-Ando et al., 2017; Chatterjee et al., 2019; Bamford et al., 2020; Morris et al., 2020).