The Relationship Between Plasma Cytokine Levels and Response to Selective Serotonin Reuptake Inhibitor Treatment in Children and Adolescents with Depression and/or Anxiety Disorders

Objective: In adults there is growing evidence that antidepressant (AD) treatment results in a decline in inflammatory cytokines. This is the first report, to our knowledge, of the relationship between response to selective serotonin reuptake inhibitor (SSRI) treatment for anxiety and/or depression and cytokine levels in children and adolescents. Methods: Forty-one patients who met Diagnostic and Statistical Manual for Mental Disorders, 4th ed. (DSM-IV) criteria for major depressive disorder (MDD) or anxiety disorders participated in study. Their ages ranged from 9 to 18 (14.122.30) years. The patients were treated with fluoxetine for 8 weeks. Plasma concentrations of tumor necrosis factor (TNF)-, interleukin (IL)-6, and IL-1 were measured by enzyme linked immunosorbent assays (ELISA) before and after fluoxetine treatment. Clinical response was measured with several scales, including the Children's Depression Rating Scale-Revised (CDRS-R), the Beck Depression Inventory (BDI), and the Screen for Child Anxiety Related Emotional Disorders (SCARED) Results: The overall response rate was 56%. Antidepressant treatment significantly reduced TNF- levels (p=0.037), with no significant changes in the levels of IL-6 and IL-1. All three proinflammatory cytokines were significantly (p < 0.05) higher in SSRI-refractory than in SSRI-responsive patients. Conclusions: Higher levels of TNF-α, IL-6, and IL-1β might predict nonresponse to fluoxetine treatment in children.