NRXN1 and attention deficit-hyperactivity disorder: Individuals with NRXN1 deletions also show symptoms of attention deficit hyperactivity disorder (ADHD, Ching et al., 2010; Schaaf et al., 2012), obsessive compulsive disorder (OCD) (Castronovo et al., 2020) and are at increased risk of developing Tourette's syndrome (TS, odds ratio = ~20.3, Huang et al., 2017) and schizophrenia (ScZ, odds ratio = ~14.4, Marshall et al., 2017).