• The cerebrospinal fluid levels of norepinephrine and six monoamine metabolites were measured in 23 patients meeting DSM-III criteria for major depressive episode, 15 of whom also met criteria for melancholia. Life events during the six-month period before the onset of depression were recorded using Paykel's method. There was no difference in Hamilton depression ratings between patients with life events and those without. However, depressed patients who did not have a life event in the six months before the onset of depression had significantly lower levels of the dopamine metabolite homovanillic acid and the serotonin metabolite 5-hydroxyindoleacetic acid than those with life events. The incidence of nonsuppression on the dexamethasone suppression test was also greater in patients with a major depressive episode who did not have an undesirable life event than in those who did. Thus, the presence or absence of life events led to a separation into biologically distinct groups.
Roy A, Pickar D, Linnoila M, Doran AR, Paul SM. Cerebrospinal Fluid Monoamine and Monoamine Metabolite Levels and the Dexamethasone Suppression Test in DepressionRelationship to Life Events. Arch Gen Psychiatry. 1986;43(4):356-360. doi:10.1001/archpsyc.1986.01800040066010