Suicidal ideation is associated with nighttime wakefulness in a community sample

Area of Science:

• Sleep science
• Psychiatry
• Public health

Background:

• Nocturnal wakefulness is a known risk factor for suicide in clinical settings.
• Research has not extensively explored this in general populations or compared it with sleep duration and quality.
• The timing of wakefulness, not just duration, may impact suicidal ideation.

Purpose of the Study:

• To investigate the association between the timing of wakefulness (nocturnal vs. morning) and suicidal ideation.
• To examine these associations on both weekdays and weekends in a general adult population.
• To compare the impact of nocturnal and morning wakefulness on suicidal ideation.

Main Methods:

• 888 adults aged 22-60 participated in the Sleep and Healthy Activity, Diet, Environment, and Socialization study.
• Suicidal ideation was assessed using the Patient Health Questionnaire-9 (PHQ-9).
• Sleep Timing Questionnaire data were used to estimate nocturnal (11 pm-5 am) and morning (5 am-11 am) wakefulness, analyzed via binomial logistic regressions.

Main Results:

• Nocturnal wakefulness was positively associated with suicidal ideation on weekdays (OR: 1.44) and weekends (OR: 1.22).
• Morning wakefulness was negatively associated with suicidal ideation on weekdays (OR: 0.82) and weekends (OR: 0.84).
• These associations persisted after adjusting for sociodemographic factors and, for nocturnal wakefulness, even after accounting for insomnia, sleep duration, quality, and chronotype.

Conclusions:

• Wakefulness during the night (11 pm-5 am) is consistently associated with suicidal ideation across weekdays and weekends.
• Wakefulness during the morning (5 am-11 am) showed a negative association with suicidal ideation in some analyses.
• Further longitudinal studies in general populations are recommended to confirm these findings regarding sleep timing and suicidal ideation.