An increase in IL-6 levels at 6-month follow-up visit is associated with SSRI-emergent suicidality in high-risk children and adolescents treated with fluoxetine.

Major depressive disorder (MDD) is associated with alterations in circulatory cytokines, in adults as well as in children and adolescents. Administration of selective serotonin reuptake inhibitors (SSRIs) to MDD pediatric patients modifies cytokine levels. However, most studies only assessed changes over a short time period. In this study, we evaluated long-term effects of the SSRI fluoxetine (FLX) in children and adolescents treated for anxiety and/or MDD, including a high-risk group with pre-treatment suicidality. The study group included ninety-two patients (35 boys and 57 girls) with MDD and/or anxiety disorders, aged 13.90 ± 2.41 years. All patients were treated with FLX and followed for 6 months. The study group included children with pretreatment suicidality (high-risk group;N = 62) and without pretreatment suicidality (N = 30) according to the Columbia Suicide Severity Rating Scale. Plasma concentrations of TNFα, IL-6, and IL-1ß were measured by enzyme linked immunosorbent assays before and after six months of treatment. IL-6 and IL-1ß significantly increased as a factor of time after 6 months of treatment. The elevation was statistically significant confined to children with pretreatment suicidality. Within the children with pretreatment suicidality, IL-6 levels increased significantly after 6 months only in the children who developed SSRI-associated suicidality. To summarize, an increase in IL-6 levels after 6 months of treatment may be associated with SSRI-emergent suicidality in children with pretreatment suicidality. Further studies are needed to clarify the role and mechanism(s) of IL-6 in the pathogenesis of this life-threatening adverse event.

Increased circulatory IL-6 during 8-week fluoxetine treatment is a risk factor for suicidal behaviors in youth.

OBJECTIVE: Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat anxiety and/or depression in pediatric populations. However, the response rates are low (approximately 50%). Moreover, SSRI use is frequently associated with adverse events (AE). Currently there are no available biomarkers for treatment response/AE. Identification of biomarkers predicting early response and/or AE could help maximize the benefit-risk ratio for the use of SSRIs, and accelerate matching of treatments to patients. Pro-inflammatory cytokines were proposed as potential biomarkers. METHOD: Ninety-two patients (35 boys and 57 girls) with major depressive disorder and/or anxiety disorders, aged 13.90 ±â€¯2.41 years, were treated with fluoxetine (FLX) for 8 weeks. Plasma concentrations of TNFα, IL-6, and IL-1ß were measured by enzyme linked immunosorbent assays before and after FLX treatment. Clinical response and AE were measured using several clinical scales, including the Clinical Global Impression - improvement, Children's Depression Rating Scale-Revised, the Beck Depression Inventory, the Screen for Child Anxiety Related Emotional Disorders, the Columbia suicide severity rating scale, and the Suicide Ideation Questionnaire. RESULTS: IL-6 levels increased after treatment only in the group of children who developed FLX-associated suicidality. CONCLUSION: An increase in IL-6 levels during treatment may be a risk factor for the emergence of FLX-associated suicidality (OR = 1.70). Further studies are necessary to clarify the role and mechanism(s) of this cytokine in the pathogenesis of this life-threatening AE.

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 (14.12 ± 2.30) years. The patients were treated with fluoxetine for 8 weeks. Plasma concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1ß 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-α levels (p = 0.037), with no significant changes in the levels of IL-6 and IL-1ß. 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-1ß might predict nonresponse to fluoxetine treatment in children.