However, we propose that the ostensible paradox of contradictory results obtained by various research groups might be explained in such a way that similar variabilities in OXTR polymorphisms or DNA methylation may occur in both patients suffering from different diseases (especially mental disorders) and healthy controls; however, the effects of specific SNPs or levels of methylation can be significantly more pronounced in affected persons due to their influence on ongoing pathological processes and enhancement of symptoms. Here, OXTR is linked to mental disorder.