Suicidal ideation and suicide attempts: associations with sleep duration, insomnia, and inflammation

Psychol Med. 2021 Sep;51(12):2094-2103. doi: 10.1017/S0033291720000860. Epub 2020 Apr 23.


Background: Sleep disturbance has been consistently identified as an independent contributor to suicide risk. Inflammation has emerged as a potential mechanism linked to both sleep disturbance and suicide risk. This study tested associations between sleep duration, insomnia, and inflammation on suicidal ideation (SI) and history of a suicide attempt (SA).

Methods: Participants included 2329 adults with current or remitted depression and/or anxiety enrolled in the Netherlands Study of Depression and Anxiety. Sleep duration, insomnia, past week SI, and SA were assessed with self-report measures. Plasma levels of C-reactive protein, interleukin-6, and tumor necrosis factor-α were obtained.

Results: Short sleep duration (⩽6 h) compared to normal sleep duration (7-9 h) was associated with reporting a prior SA, adjusting for covariates [adjusted odds ratio (AOR) 1.68, 95% CI 1.13-2.51]. A higher likelihood of SI during the past week was observed for participants with long sleep duration (⩾10 h) compared to normal sleep duration (AOR 2.22, 95% CI 1.02-4.82), more insomnia symptoms (AOR 1.44, 95% CI 1.14-1.83), and higher IL-6 (AOR 1.31, 95% CI 1.02-1.68). Mediation analyses indicated that the association between long sleep duration and SI was partially explained by IL-6 (AOR 1.02, 95% CI 1.00-1.05).

Conclusions: These findings from a large sample of adults with depression and/or anxiety provide evidence that both short and long sleep duration, insomnia symptoms, and IL-6 are associated with the indicators of suicide risk. Furthermore, the association between long sleep duration and SI may operate through IL-6.

Keywords: Anxiety; depression; inflammation; insomnia; sleep; suicide.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Humans
  • Inflammation / epidemiology
  • Interleukin-6
  • Risk Factors
  • Sleep
  • Sleep Initiation and Maintenance Disorders* / epidemiology
  • Sleep Wake Disorders*
  • Suicidal Ideation
  • Suicide, Attempted


  • Interleukin-6