Insomnia and circadian rhythms dysregulation in people who have attempted suicide: correlations with markers of inflammation and suicidal lethality.

Introduction: Suicide is a widespread problem, with risk factors still a challenge. The aim was to assess correlations among insomnia, circadian rhythm, and inflammatory markers in individuals who attempted suicide.

Materials and methods: Consecutive patients hospitalised following an attempted suicide, were assessed. Psychiatric diagnosis (DSM-5-TR Criteria), lethality of the suicide attempt (Suicide Intent Scale-SIS), and inflammatory parameters NLR (neutrophil-lymphocyte ratio) PLR (platelet-lymphocyte ratio), and SII (systemic inflammation index/neutrophil-to-platelet ratio on lymphocytes), were computed. Depressive and manic symptoms (Beck Depression Inventory-BDI-II, Young Mania Rating Scale- YMRS), circadian rhythms disturbances (Biological Rhythms Interview of Assessment in Neuropsychiatry-BRIAN), insomnia symptoms (Insomnia Severity Index-ISI) were assessed together with socio-demographic, clinical and pharmacological data.

Results: The final sample included 52 individuals. Patients who experienced insomnia during the preceding two weeks utilised high lethality methods, reported heightened dysregulation of chronobiological rhythms, heightened severity of depression, and elevated levels of inflammatory markers. High lethality was best predicted by insomnia symptoms (OR = 20.1, CI-95% 4.66-87.25, p = 0.001), by disturbances of circadian rhythms (OR = 6.97, CI-95% 1.82-26.66, p = 0.005), and by NLR indices (OR 4.00, CI-95% 1.14-13.99, p = 0.030).

Conclusions: Sleep disturbances may be a risk factor for suicidal lethality, along with markers of inflammation. It is plausible that insomnia and circadian sleep dysregulation may contribute to inflammation, thereby promoting suicidal risk.