Endocrine and cytokine correlates of major depression and dysthymia with typical or atypical features

Depression has been associated with both suppression and enhancement of var ious aspects of immune functioning. It was of interest to determine whether cytokine alterations associated with depression, including interleukin-1 ( IL-1 beta) and interleukin-2 (IL-2), were related to the neurovegetative sy mptom profile or to the chronicity of the illness. Circulating ACTH, cortis ol, norepinephrine (NE) and epinephrine levels, and production of IL-1 beta and IL-2 from mitogen-stimulated lymphocytes were assessed in classical ma jor depression, atypical depression (ie. with reversed neurovegetative feat ures), and dysthymia (chronic depression without comorbid major depression) with either typical or atypical profiles, as well as nondepressed control subjects. Among atypical depressives, plasma ACTH levels were elevated whil e cortisol was reduced relative to controls. Irrespective of neurovegetativ e profile, IL-1 beta production was increased in dysthymic patients, and wa s highly correlated with age-of-onset and duration of illness. In contrast, IL-2 production was reduced in each of the groups, although less so among atypical major depressives. Moreover, IL-2 production in the depressive gro ups was directly related to plasma NE levels, While neither depressed mood per se nor neurovegetative features accounted for this effect, it seemed li kely that chronicity of illness or age-of-onset were associated with cytoki ne alterations. Given that circulating cytokines influence neuroendocrine f unctioning, and may affect neurovegetative features, a role for interleukin s may exist with respect to the pathophysiology of certain subtypes of depr ession.