It has been reported that genetic variants in the promoter region of CNR1 and serotonin transporter gene (SLC6A4) interactively increase the risk of high anxiety scores (Lazary et al., 2009), and interaction of CNR1 variants with recent negative life events is considered to be an important risk factor for development of depression symptoms (Juhasz et al., 2009a) and migraine (Juhasz et al., 2017). This evidence concerns the gene CNR1 and major depressive disorder.