Calabro et al. (2020) found that SNP rs352428 located in FZD3 was associated with depression and that G allele carriers showed a higher risk of previous depressive episode. FZD3 was also reported to be highly associated with the risk of schizophrenia (Yang et al., 2003; Zhang et al., 2004). Liu et al. (2020) found that SNP rs10252923 in FZD1 was significantly associated with schizophrenia. Voleti et al. (2012) reported Fzd6 knockdown in rat brain resulted in depressive and anxiety behaviors. Here, FZD6 is linked to schizophrenia.