C-reactive protein level in late-onset depression: A case–control study

BACKGROUND: Late-onset depression (LOD) is less responsive to standard antidepressant medication compared to early-onset depressive disorder. A group of early-onset depressive episode is less responsive to antidepressant medication, and immune dysregulation is critically involved in it. LOD has been associated with increased vascular risk factor and atherosclerosis and immune dysregulation is critically involved in vascular disease. We hypothesized that increased inflammatory activity may be associated with late-onset depressive disorders. AIM: The aim of this study is to study the C-reactive protein (CRP) levels in LOD compared with age-matched controls and association between CRP levels and severity of depressive episode. SETTINGS AND DESIGN: This was a case–control study at tertiary care psychiatry department. MATERIALS AND METHODS: Depressed patients (as per International Classification of Disease 10 Diagnostic and Research Criteria) of age >55 years were recruited and age-matched control participant were recruited after informed consent. A complete clinical assessment, assessment of vascular risk factors, blood sample for the evaluation of serum CRP was obtained, and baseline depression severity was measured on Hamilton Depression Rating Scale (HDRS). STATISTICAL ANALYSIS: The quantitative and qualitative variables were described as means, standard deviation, and P value. The student's t-test for parametric data and the mann-whitney test for nonparametric data spearman correlation coefficient method were used. RESULTS: The mean age of cases (n = 25) was 64.7 ± 5.8 years, and mean age of controls (n = 25) was 64.2 ± 3.7 years. Patients with current depressive disorders had 40% times higher levels of CRP than control. Baseline HDRS of cases was 18 ± 3. CRP level and depression severity shows strong positive (r = 0.935, P = <0.001) correlation between CRP level and depression severity. CONCLUSION: LOD was associated with higher level of CRP compared to age-matched nondepressed patients. Raised CRP was associated with severity of depressive episode of LOD.