Copy number, truncating, and missense variants in NLGN1 are associated with autism spectrum disorders (ASD) (Glessner et al., 2009; Nakanishi et al., 2017; O'Roak et al., 2012; Tejada et al., 2019) and obsessive-compulsive disorder (Gazzellone et al., 2016) and NLGN1 polymorphisms are linked to schizophrenia (Chen et al., 2018; Zhang et al., 2015). Here, NLGN1 is linked to obsessive-compulsive disorder.