Norepinephrine function in personality disorder: Plasma free MHPG correlates inversely with life history of aggression

Objective: Clinical and pre-clinical data suggest the possibility of a facilitory role for norepinephrine (NE) in impulsive-aggressive behavior. While clinical studies have focused on putative central measures of NE activity, few studies have been published using peripheral measures. In this study, the relationship between plasma free NE metabolite, plasma free 3-methoxy-4-hydroxyphenylglycol (pMHPG), and impulsive aggression was explored in subjects with personality disorder. Methods: Subjects were 30 male subjects with personality disorder in whom basal plasma free MHPG concentrations were obtained. Aggression was assessed using the Life History of Aggression (LHA) assessment and the Buss-Durkee Aggression scales; impulsivity was assessed using the Barratt Impulsiveness and the Eysenck Personality Questionnaire Impulsivity scales. Results: A significant inverse correlation was found between LHA-Aggression and pMHPG in these subjects. Correlations with other behavioral measures were not statistically significant. pMHPG was significantly lower among subjects with borderline personality disorder but not significantly lower after controlling for LHA-Aggression scores. Conclusion: These data suggest that pMHPG is inversely correlated with life history of aggression in subjects with personality disorder and that central and/or peripheral NE may play a role in modulating aggressive behavior in these subjects.