Noradrenergic responses to clonidine in acute and remitted depressed male patients

• Published in: Psychiatry research 1992-09, Vol.43 (3), p.199-213
• Main Authors: Trestman, Robert L., Lawrence, Timothy L., Coccaro, Emil F., Harvey, Philip, Bernstein, David, Lawrence, Edith K., Condello, Virginia, Mahon, Theresa, Yang, Ren-Kui, Knott, Peter, Horvath, Thomas B., Siever, Larry J.
• Format: Article
• Language: English
• Subjects: 3-methoxy-4-hydroxyphenylglycol; Acute Disease; Adult and adolescent clinical studies; Affective disorder; Aged; Arousal - drug effects; Arousal - physiology; Biological and medical sciences; Bipolar Disorder - blood; Bipolar Disorder - diagnosis; Bipolar Disorder - psychology; Blood Pressure - drug effects; Blood Pressure - physiology; Clonidine; Cohort Studies; Depression; Depressive Disorder - blood; Depressive Disorder - diagnosis; Depressive Disorder - psychology; Follow-Up Studies; heart rate; Heart Rate - drug effects; Heart Rate - physiology; Humans; Infusions, Intravenous; Male; mean arterial pressure; Medical sciences; Methoxyhydroxyphenylglycol - blood; Middle Aged; Mood disorders; Norepinephrine - physiology; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Receptors, Adrenergic - drug effects; Receptors, Adrenergic - physiology
• ISSN: 0165-1781; 1872-7123
• DOI: 10.1016/0165-1781(92)90053-6

To investigate noradrenergic function in depression, plasma 3-methoxy-4-hydroxyphenylglycol (MHPG), plasma norepinephrine (NE), mean arterial pressure (MAP), and heart rate responses to intravenous clonidine (2 μ/kg), an α 2-adrenergic agonist, were measured in 27 acutely depressed patients, 18 remitted depressed patients, and 27 normal control subjects; a placebo infusion was administered to a subgroup. Clonidine compared with placebo, over a 150-minute time course, decreased plasma NE, MAP, and heart rate, but not plasma MHPG, in the control subjects. Plasma MHPG, plasma NE, MAP, and heart rate at baseline or in response to clonidine and placebo over 150 minutes did not indicate any group differences. The only significant plasma MHPG response to clonidine in the normal control subjects occurred 60 minutes after the infusion. A significantly diminished plasma MHPG response to clonidine at 60 minutes was found in the acutely depressed group compared with the normal control subjects. These results suggest that peripheral inhibitory noradrenergic responses to clonidine are normal in depressed patients, while plasma MHPG responses to clonidine, which have a limited central contribution, appear to be a weak reflection of central noradrenergic function and appear insufficiently robust for a meaningful evaluation of hypothetical group differences in central inhibitory α 2-adrenergic activity in this population.