Association of depressive disorders, depression characteristics and antidepressant medication with inflammation

Growing evidence suggests that immune dysregulation may be involved in depressive disorders, but the exact nature of this association is still unknown and may be restricted to specific subgroups. This study examines the association between depressive disorders, depression characteristics and antidepressant medication with inflammation in a large cohort of controls and depressed persons, taking possible sex differences and important confounding factors into account. Persons (18–65 years) with a current (N=1132) or remitted (N=789) depressive disorder according to DSM-IV criteria and healthy controls (N=494) were selected from the Netherlands Study of Depression and Anxiety. Assessments included clinical characteristics (severity, duration and age of onset), use of antidepressant medication and inflammatory markers (C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α)). After adjustment for sociodemographics, currently depressed men, but not women, had higher levels of CRP (1.33 versus 0.92 mg l−1, P<0.001, Cohen's d=0.32) and IL-6 (0.88 versus 0.72 pg ml−1, P=0.01, Cohen's d=0.23) than non-depressed peers. Associations reduced after considering lifestyle and disease indicators — especially body mass index — but remained significant for CRP. After full adjustment, highest inflammation levels were found in depressed men with an older age of depression onset (CRP, TNF-α). Furthermore, inflammation was increased in men using serotonin–norepinephrine reuptake inhibitors (CRP, IL-6) and in men and women using tri- or tetracyclic antidepressants (CRP), but decreased among men using selective serotonin reuptake inhibitors (IL-6). In conclusion, elevated inflammation was confirmed in depressed men, especially those with a late-onset depression. Specific antidepressants may differ in their effects on inflammation

Inflammatory and Metabolic Dysregulation and the 2-Year Course of Depressive Disorders in Antidepressant Users

Scarce evidence suggests that inflammatory and metabolic dysregulation predicts poor response to antidepressants, which could result in worse depression outcome. This study prospectively examined whether inflammatory and metabolic dysregulation predicted the 2-year course of depressive disorders among antidepressant users. Data were from the Netherlands Study of Depression and Anxiety, including 315 persons (18-65 years) with a current depressive disorder (major depressive disorder, dysthymia) at baseline according to the DSM-IV criteria and using antidepressants. Inflammatory (C-reactive protein, interleukin-6 (IL-6), tumor-necrosis factor-a) and metabolic (waist circumference, triglycerides, high-density lipoprotein (HDL) cholesterol, blood pressure, fasting glucose) factors were measured at baseline. Primary outcome for course of depression was indicated by whether or not a DSM-IV depressive disorder diagnosis was still/ again present at 2-year follow-up, indicating chronicity of depression. Elevated IL-6, low HDL cholesterol, hypertriglyceridemia, and hyperglycemia were associated with chronicity of depression in antidepressant users. Persons showing 4 inflammatory or metabolic dysregulations had a 1.90 increased odds of depression chronicity (95% Cl = 1.12-3.23). Among persons who recently (ie, at most 3 months) started antidepressant medication (N= 103), having >= 4 dysregulations was associated with a 6.85 increased odds of depression chronicity (95% Cl = 1.95-24.06). In conclusion, inflammatory and metabolic dysregulations were found to predict a more chronic course of depressive disorders among patients using antidepressants. This could suggest that inflammatory and metabolic dysregulation worsens depression course owing to reduced antidepressant treatment response and that alternative intervention treatments may be needed for depressed persons with inflammatory and metabolic dysregulation

Evidence for a differential role of HPA-axis function, inflammation and metabolic syndrome in melancholic versus atypical depression

<p>The hypothalamic-pituitary-adrenal (HPA) axis and the inflammatory response system have been suggested as pathophysiological mechanisms implicated in the etiology of major depressive disorder (MDD). Although meta-analyses do confirm associations between depression and these biological systems, effect sizes vary greatly among individual studies. A potentially important factor explaining variability is heterogeneity of MDD. Aim of this study was to evaluate the association between depressive subtypes (based on latent class analysis) and biological measures. Data from 776 persons from the Netherlands Study of Depression and Anxiety, including 111 chronic depressed persons with melancholic depression, 122 with atypical depression and 543 controls were analyzed. Inflammatory markers (C-reactive protein, interleukin-6, tumor necrosis factor-alpha), metabolic syndrome components, body mass index (BMI), saliva cortisol awakening curves (area under the curve with respect to the ground (AUCg) and with respect to the increase (AUCi)), and diurnal cortisol slope were compared among groups. Persons with melancholic depression had a higher AUCg and higher diurnal slope compared with persons with atypical depression and with controls. Persons with atypical depression had significantly higher levels of inflammatory markers, BMI, waist circumference and triglycerides, and lower high-density lipid cholesterol than persons with melancholic depression and controls. This study confirms that chronic forms of the two major subtypes of depression are associated with different biological correlates with inflammatory and metabolic dysregulation in atypical depression and HPA-axis hyperactivity in melancholic depression. The data provide further evidence that chronic forms of depressive subtypes differ not only in their symptom presentation, but also in their biological correlates. These findings have important implications for future research on pathophysiological pathways of depression and treatment.</p>