GPM6A and depressive disorder: In humans, alterations in M6a levels or polymorphisms in GPM6A, are associated with depression, schizophrenia, claustrophobia, bipolar disorders, and learning disabilities (Boks et al., 2008; Greenwood et al., 2012; El-Kordi et al., 2013; Gregor et al., 2014; Fuchsova et al., 2015).