The total resting plasma catecholamine concentration from 13 drugfree, depressed patients was found to be significantly elevated over concentrations from 47 normal controls. Differential determinations of epinephrine and norepinephrine revealed that both catecholamine components were elevated in the Patients. The literature on norepinephrine concentrations in brain, spinal fluid, and urinary excretion was reviewed and indicated that rather than being decreased, norepinephrine has been found to be either unchanged or increased in depressed patients.
Wyatt RJ, Portnoy B, Kupfer DJ, Snyder F, Engelman K. Resting Plasma Catecholamine Concentrations in Patients With Depression and Anxiety. Arch Gen Psychiatry. 1971;24(1):65-70. doi:10.1001/archpsyc.1971.01750070067009