OPRM1 and Borderline personality disorder: Overstimulation of the EOS by excessive stress from physical or even social threat, as well as reduced basal opioidergic stimulation, can lead to an adapted receptor expression and an imbalance of the KOR-MOR relationship, resulting in symptoms resembling BPD, such as dysphoria, increased affective irritability and impulsivity, and interpersonal dysfunction [6, 7, 14, 15].