Pro-inflammatory cytokines and suicidality in patients with bipolar disorder
Leo Sher, M.D.
A research report, “Pro-inflammatory cytokines and suicidal behavior among patients with bipolar I disorder” is published in the June 2022 issue of the Journal of Psychiatric Research (1). The authors compared the levels of proinflammatory cytokines in bipolar disorder patients with or without suicidal ideation, and between patients with or without a history of suicide attempt.
Patients with bipolar I disorder and age and sex matched healthy controls were recruited. Patients were divided into two groups: with suicidal ideation and without suicidal ideation. Suicidal ideation was defined by a score of ≥1 on item 10 of Montgomery Åsberg Depression Rating Scale. Levels of proinflammatory cytokines, including soluble interleukin-6 receptor, soluble tumor necrosis factor-α receptor type 1, and C-reactive protein, were measured.
Patients with suicidal ideation had a higher rate of suicide attempt history in comparison to patients without suicidal ideation (61.9% vs. 28.6%). Patients with suicidal ideation had higher levels of soluble tumor necrosis factor-α receptor type 1 than patients without suicidal ideation and healthy controls. Bipolar disorder patients with or without a history of suicide attempt had higher levels of C-reactive protein than healthy controls. Linear regression analyses showed that serum levels of soluble interleukin-6 receptor and soluble tumor necrosis factor-α receptor type 1 were positively associated with suicidal ideation after controlling for demographic data, depression and mania severity. The authors suggest that their findings strengthen the hypothesis of a link between neuro-inflammation and suicidality.
- Huang MH, Chen MH, Chan YE, Li CT, Tsai SJ, Bai YM, Su TP. Pro-inflammatory cytokines and suicidal behavior among patients with bipolar I disorder. J Psychiatr Res. 2022 Jun;150:346-352. doi: 10.1016/j.jpsychires.2021.11.030. Epub 2021 Nov 22.