Interleukin-1beta serum levels is increased in antidepressant-free elderly depressed patients.

OBJECTIVE: To assess the serum levels of interleukin 1beta (IL-1beta) in elderly depressed patients in comparison with nondepressed healthy elderly subjects.
DESIGN: Cross-sectional study.
SETTING: Tertiary memory clinic. PARTICIPANTS: Twenty-three antidepressant-free elderly depressed patients and 44 nondepressed healthy elderly comparison group were enrolled to this study. MEASUREMENT: Serum IL-1beta levels were determined with highly sensitive colorimetric sandwich enzyme-linked immunosorbent assay. Severity of the depressive episode was determined by scores on the Hamilton Depression Scale-21 item and cognitive performance by the scores on the Cambridge Cognition Examination, Mini Mental State Examination clock drawing test, and verbal fluency.
RESULTS: IL-1beta serum levels were increased in elderly patients versus nondepressed elderly (t = 2.21, df = 65, p = 0.04). After categorizing elderly depressed subjects into late onset (LOD) versus early onset (EOD), patients with EOD had the highest IL-1beta levels, when compared with nondepressed elderly patients and patients with LOD in analysis of variance (F = 4.9, df = 2, 64, p <0.01).
CONCLUSIONS: Late-life depression is associated with higher IL-1beta levels suggesting that increased proinflammatory state may play a role in the physiopathology of depression in the elderly. The authors further show that this might be more prominent in those patients with EOD geriatric depression.