Inflammatory Markers Profile in Older Adolescents During Treatment with Selective Serotonin Reuptake Inhibitors

This study aimed to investigate the serum levels of inflammatory markers in adolescents with major depressive disorder (MDD) using selective serotonin reuptake inhibitors. This was an 8-month observational study, involving 30 adolescents with and 38 without (control) MDD diagnosis. Demographic (age and gender) and anthropometric data (weight, height, and calculated body mass index [BMI] z score) were collected. Body composition was assessed with whole-body DXA scan. Depressive and anxiety symptoms were assessed using the Beck Depression and Anxiety Inventories (BDI-II and BAI), respectively. Serum levels of interleukin (IL)-6, IL-8, IL-1β, tumor necrosis factor, monocyte chemoattractant protein-1 (MCP-1), leptin, resistin, and adiponectin were measured using Bio-Plex Multiplex Immunoassays at baseline and after 8 months. At baseline, patients with MDD and controls did not differ in age, gender, BMI z score, and fat mass index (FMI) z score. At follow-up, 58.3% (21/36) of patients with MDD were in full remission. Patients with MDD had higher levels of resistin at baseline (26274.16 pg/mL [16162.68-54252.72]) than controls (21678.53 pg/mL [11221.17-37343.27]; p < 0.01). This difference remained statistically significant after adjustment for sex, age, and FMI z score. No differences in other inflammatory markers were observed between the groups. By follow up, depressive and anxiety symptom severity had decreased significantly in patients with MDD in parallel with a decrease in the serum levels of TNF (p = 0.02), IL-8 (p < 0.01) and MCP-1 (p = 0.04). Among these markers, BDI-II score was positively correlated with serum levels of MCP-1. These results corroborate the view of involvement of peripheral inflammatory mechanisms in the pathophysiology of MDD in adolescents. This trial is registered at ClinicalTrials.gov: NCT02147184.