Year: 2021 Source: The World Journal of Biological Psychiatry. (2021). DOI: 10.1080/15622975.2021.1988703 SIEC No: 20210892

Objectives: To explore the link between cytokines and suicide attempts and their relationship
with the psychological aspects of this complex multifactorial phenomenon.
Methods: 96 participants, including 20 patients with a recent suicide attempt and diagnosis of
Major Depression Disorder (MDD), 33 MDD patients with a lifetime history of suicide attempt,
23 non-attempter MDD patients, and 20 healthy controls underwent an assessment on depressive symptoms, global functioning, aggressive behaviour, presence of abuse and attention performance. Additionally, all participants had a blood extraction for IL-2, IL2-R, IL-4, IL-6, and TNF-a
plasma levels analysis.
Results: IL-6 levels were significantly different across groups (F(3,89)¼3.690; p ¼ 0.015), with
higher concentrations in both recent (p ¼ 0.04) and distant (p ¼ 0.015) attempt in comparison to
MDD non-attempters. IL-6 was associated with adult physical abuse (B ¼ 2.591; p ¼ 0.021), lower
global functioning score (B ¼ 0.512; p ¼ 0.011), and poorer performance on attention (B ¼
0.897; p ¼ 0.011).
Conclusions: Recent and distant suicidal behaviour is associated with elevated IL-6 levels, which
may be influenced by stressful and traumatic experiences. Elevated concentrations of IL-6 could
have a negative impact on attention, increasing suicide risk. More research is needed to clarify
the role of cytokines in suicide-related features to explore novel treatments and more effective
preventive interventions