INTERLEUKIN-1-BETA - A PUTATIVE MEDIATOR OF HPA AXIS HYPERACTIVITY INMAJOR DEPRESSION

Objective: There is extensive evidence that major depression, and part icularly melancholia, is characterized by hypothalamic-pituitary-adren al (HPA) axis hyperactivity as well as systemic immune activation, whi ch may be accompanied by increased interleukin-1beta production. Inter leukin-1beta is known to enhance HPA axis activity during an immune re sponse. This study investigated whether interleukin-1beta production i s related to HPA axis activity in depressed subjects. Method: The subj ects were 28 inpatients with major or minor depression and 10 normal c omparison subjects. The authors measured 1) the subjects' cortisol lev els after an overnight 1-mg dexamethasone suppression test (DST) and 2 ) mitogen-stimulated supernatant interleukin-1beta production by perip heral blood mononuclear cells. Results: Statistically significant posi tive correlations between interleukin-1beta production and post-DST co rtisol values were found in the study group as a whole and in the depr essed and normal subgroups separately. Conclusions: It is suggested th at constituents of the immune response (such as interleukin-1beta) in major depression may contribute to HPA axis hyperfunction in that illn ess.