Leo Sher, M.D.

A research report, “Increased circulatory IL-6 during 8-week fluoxetine treatment is a risk factor for suicidal behaviors in youth” has been published in Brain, Behavior, and Immunity online ahead of print (1). The authors examined whether fluoxetine treatment of adolescents with anxiety and/or depression influences levels of the pro-inflammatory cytokines tumor necrosis factor alpha (TNFα), interleukin 6 (IL-6), and interleukin 1 beta (IL-1β); whether plasma levels of these pro-inflammatory cytokines can predict response to fluoxetine treatment; and whether these pro-inflammatory cytokines can predict adverse events, particularly suicidal behavior, during fluoxetine treatment.

Ninety-two adolescent (35 boys and 57 girls) with major depressive disorder and/or anxiety disorders, aged 13.90 ± 2.41 years, were treated with fluoxetine for 8 weeks. Plasma concentrations of TNFα, IL-6, and IL-1β were measured before and after fluoxetine treatment. Clinical response and adverse events were measured using several psychometric 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.

The authors found that IL-6 levels increased after treatment only in the group of adolescents who developed suicidality. The authors proposed that an increase in IL-6 levels during fluoxetine treatment may be a risk factor for the emergence of suicidality. The result of this study is consistent with growing evidence that inflammation, as manifested by increased levels of pro-inflammatory cytokines and inflammatory chemokines, is associated with suicidality.

Reference

1. Amitai M, Taler M, Ben-Baruch R, Lebow M, Rotkopf R, Apter A, Fennig S, Weizman A, Chen A. Increased circulatory IL-6 during 8-week fluoxetine treatment is a risk factor for suicidal behaviors in youth. Brain Behav Immun. 2019 Dec 27. pii: S0889-1591(19)31330-3. doi: 10.1016/j.bbi.2019.12.017. [Epub ahead of print]