The Mind After Midnight: Mechanistic Examination of Nocturnal Wakefulness as a Suicide Risk Factor
University of Arizona
Summary
This study examines whether wakefulness during the biological night (2:00-4:00 AM) is associated with increased negative mood, impaired decision-making, and suicidal thoughts. Adults with a history of suicidal ideation in the past six months will complete laboratory and home-based assessments under varying levels of sleep pressure. Participants will be evaluated during late-night wakefulness and under conditions of both higher and lower sleep pressure. The goal of the study is to better understand the biological and behavioral mechanisms that may contribute to elevated suicide risk during nocturnal wakefulness.
Description
Suicide risk is elevated during the biological night, particularly between 2:00 and 4:00 AM. Observational and epidemiologic data suggest that nocturnal wakefulness is associated with increased negative affect, impaired decision-making, and greater suicidal ideation. The "Mind After Midnight" hypothesis proposes that wakefulness during the biological night exposes individuals to a combination of circadian vulnerability and homeostatic sleep pressure that contributes to emotional and cognitive dysregulation. This study will recruit approximately 90 adults with a history of suicidal ideation in…
Eligibility
- Age range
- 18–55 years
- Sex
- All
- Healthy volunteers
- No
Inclusion Criteria * Age 18-55 years * History of suicidal ideation within the past 6 months * Habitual bedtime between 9:00 PM and 1:00 AM * Habitual wake time between 6:00 AM and 9:00 AM * Ability to provide informed consent Exclusion Criteria: * Current suicidal intent requiring immediate clinical intervention * Diagnosis of a primary sleep disorder (e.g., untreated obstructive sleep apnea, narcolepsy) * Bipolar disorder or psychotic disorder * Substance use disorder within the past 3 months * Use of medications that significantly affect sleep or circadian rhythms * Night shift work or t…
Interventions
- BehavioralSleep Pressure Manipulation
Participants undergo an experimental manipulation of homeostatic sleep pressure involving controlled wakefulness or scheduled awakening during the biological night. Mood, suicidal ideation, impulsivity, and decision-making are assessed during overnight laboratory sessions.
Location
- University of Arizona - Center for Sleep, Circadian, and Neuroscience ResearchTucson, Arizona