Immunological changes in depression.

Background: The role of Immune system in the pathophysiology of depressive disorders is a field of active research, however Indian literature is sparse. The present study was planned to assess the immunological response in depression.

Materials and Methods: The study comprised of 100 subjects. There were fifty cases of depression satisfying the ICD-10 criteria with no physical illness and HIV negative status and fifty age and sex matched healthy volunteers. Depression was assessed on HRSD and BDI scales. Assessment of three markers each of cellular immunity (NK cells, CD4, CD8 cells) and humoral immunity (Il-2, IL-6 and CRP) was carried out on both groups and depressed patients were reassessed on all parameters after 08 weeks of treatment with antidepressants (SSRIs or TCAs).

Results: NK Cells were significantly higher in the depressed group and CD 8 Cells and CD 4 Cells were higher in the control group ( P = 0.001). Depressed group before treatment v/s control group differed significantly in the cell mediated immune markers. IL-2 levels were higher in the control group. The markers of cell mediated immunity i.e., NK cells, CD4, CD8 had increased significantly after treatment ( P =< 0.001). The humoral immunity markers (CRP and IL-2) decreased significantly after treatment ( P =< 0.001). However IL -6 levels were raised significantly in the subjects after treatment ( P =< 0.001).

Conclusion: Dysregulation of immune response occurs in depressed patients with changes in both cell mediated and humoral immunity. Further, antidepressant treatment affects the immune status of depressed patients.