Mind After Midnight (MaM)

May 19, 2026 updated by: MICHAEL A GRANDNER, University of Arizona

The Mind After Midnight: Mechanistic Examination of Nocturnal Wakefulness as a Suicide Risk Factor

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.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed 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 the past six months. Participants will complete both home-based and laboratory-based procedures. Laboratory assessments will evaluate mood, hopelessness, suicidal ideation, impulsivity, and decision-making at different times of day, including 2:00-4:00 AM. To examine the role of homeostatic sleep pressure, participants will complete late-night assessments under two conditions: (1) high sleep pressure (remaining awake until 2:00 AM) and (2) low sleep pressure (sleeping and being awakened at 2:00 AM). Circadian factors will be assessed using behavioral measures and physiologic markers, including melatonin.

The goal of the study is to experimentally test whether nocturnal wakefulness contributes to suicide-associated cognitive and affective processes and to identify underlying chronobiological mechanisms.

Study Type

Interventional

Enrollment (Estimated)

90

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Arizona
      • Tucson, Arizona, United States, 85724
        • Recruiting
        • University of Arizona - Center for Sleep, Circadian, and Neuroscience Research
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

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 transmeridian travel within the past month
  • Medical or neurological condition that would interfere with participation
  • Pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: High Sleep Pressure Condition
Participants will remain awake until 2:00 AM to induce high homeostatic sleep pressure. During the biological night (2:00-4:00 AM), participants will complete assessments of mood, suicidal ideation, impulsivity, and decision-making under conditions of sustained wakefulness.
Behavioral: Sleep 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.
Experimental: Low Sleep Pressure Condition
Participants will be allowed to sleep and will be awakened at 2:00 AM to induce lower homeostatic sleep pressure. During the biological night (2:00-4:00 AM), participants will complete assessments of mood, suicidal ideation, impulsivity, and decision-making following sleep and acute awakening.
Behavioral: Sleep 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Feelings of Hopelessness
Time Frame: Visit 1(day 2, night 2), Visit 2 (day 2, night 2)
Total score on the BECK Hopelessness scale (BHS)
Visit 1(day 2, night 2), Visit 2 (day 2, night 2)
Impaired Executive Function
Time Frame: Visit 1(day 2, night 2), Visit 2 (day 2, night 2)
BART total score
Visit 1(day 2, night 2), Visit 2 (day 2, night 2)
Negative Mood
Time Frame: Visit 1(day 2, night 2), Visit 2 (day 2, night 2)
PANAS negative affect score
Visit 1(day 2, night 2), Visit 2 (day 2, night 2)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Arizona

Collaborators

National Institute of Mental Health (NIMH)

Investigators

  • Principal Investigator: Michael A Grandner, PhD, University of Arizona

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 6, 2026

Primary Completion (Estimated)

February 28, 2029

Study Completion (Estimated)

August 31, 2029

Study Registration Dates

First Submitted

February 11, 2026

First Submitted That Met QC Criteria

February 23, 2026

First Posted (Actual)

February 27, 2026

Study Record Updates

Last Update Posted (Actual)

May 22, 2026

Last Update Submitted That Met QC Criteria

May 19, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • R01MH135978 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Sleep Wake Disorders

Clinical Trials on Sleep Pressure Manipulation

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Cyprus

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe