GH response to intravenous clonidine challenge: absence of relationship with behavioral irritability, aggression, or impulsivity in human subjects.

Previous study suggests a role for post-synaptic alpha(2)-noradrenergic receptor sensitivity in irritability and/or aggression and impulsivity. In this study, we conducted intravenous challenges with the alpha(2)-noradrenergic agonist, clonidine, to assess the relationship between measures of impulsive aggression and post-synaptic alpha(2)-noradrenergic receptor sensitivity in human subjects. Subjects included 38 individuals with personality disorder and 28 healthy volunteer controls. Measures included the Irritability score and the Total Assault score from the Buss-Durkee Hostility Inventory (BDHI), Aggression score from Life History of Aggression (LHA) assessment, and Impulsivity scores from the Barratt Impulsivity Scale (BIS-11) and Eysenck Personality Questionnaire-II (EPQ-II). The Log of Peak DeltaGH[CLON] response was used as the index of post-synaptic alpha(2)-noradrenergic receptor sensitivity. No significant correlations were found between the Log of Peak DeltaGH[CLON] response and any measure used in this study. Unlike a previous investigation, this study provides little support for a role of post-synaptic alpha(2)-noradrenergic receptor sensitivity in aggression in healthy or personality disordered subjects.