Pain Sensitization and Habituation in a Model of Experimentally-induced Insomnia Symptoms
Condition: Sleep Control Condition; Insomnia Symptoms Induction Condition
MeSH terms: Sleep Initiation and Maintenance Disorders; Disease
Study type: Interventional

Summary: 
      The main purpose of this study is to learn about the effects of repeated exposure to sleep
      disruption (3 cycles of sleep disruption, each consisting of three days in a row where sleep
      is shortened and disrupted, followed by a single night of recovery sleep) on inflammation,
      mood, and pain processing (experiences/perceptions of pain). Purpose of this research project
      is to understand the mechanisms of how sleep disruption may change mood and the experience of
      pain. Understanding those mechanisms is important to develop interventions that may help to
      reduce the effects of sleep disruption on mood and pain.
    

Detailed description: 
      1. Screening Procedures: For this research study, the screening procedures include the
           following activities. Participants will first complete questionnaires and have an
           interview where they will be asked questions concerning general health status and
           sleep-wake habits. Also during this visit, a study nurse will collect a small blood
           sample that will be used to test for a number of markers of general health status.

           If it appears that the participant may be eligible for participation, s/he will be
           introduced to an electronic diary that will be emailed every morning and evening to
           monitor sleep-wake patterns, mood, pain, and other health-related information.

           Following the medical screening (visit 2), the physician will determine if the
           participant is eligible to proceed to the overnight sleep study. This consists of
           sleeping overnight in the laboratory during the usual sleep time.

           Seven days before participation in the in-hospital portion of the study, a member of the
           study team will ask the participant to follow the study sleep-wake schedule. Sleep will
           be monitored with an electronic sleep diary and the participant will wear an actigraphy
           watch, which will help to evaluate sleep and measure the light level exposure before
           starting the study.

        2. Randomization Procedures: Each participant will complete both parts of the study
           protocol, i.e., the experimental condition (where participants will undergo repeated
           cycles of sleep disruption, 18 days total in the Clinical Research Center) and the
           control condition (where participants will have a sleep opportunity of 8 hours every
           night; 18 days total in the Clinical Research Center).

        3. Research Procedures: If a participant qualifies to take part in this research study,
           s/he will be required to stay in the hospital for two 18 day long research protocols.
           These protocols will take place at least 2-3 months apart. The experimental protocol
           includes 3 nights of 8 hour-sleep per night followed by three 4-day cycles, each
           consisting of 3 nights of shortened and disrupted sleep, followed by a single night of 8
           hour recovery sleep. After the last cycle, the participant will have two more nights
           with 8 hours of sleep per night. In the control protocol, these 18 days will be 8-hour
           sleep nights.

           During the stay in the hospital, research staff will accompany the participant during
           all waking times. The staff will help the participant to stay on the schedule, maintain
           wakefulness, and make sure that equipment is recording properly.

           Both study protocols will begin with two adaptation nights. On the first day of the
           protocol, the participant will be told the sleep condition to be assigned first: the
           sleep disruption condition or the sleep control condition.

           During the sleep disruption nights, sleep onset will be delayed by one hour (midnight
           12am), and sleep offset (final wake up) will be advanced by one hour (6am). The sleep
           period (12-6am) will be disrupted hourly by 20 minute long awakenings. During the
           nighttime periods, the nurse will measure blood pressure and collect a small sample of
           your saliva. The participant will also be asked to complete tests that assess well-being
           and cognitive functioning (such as attention, learning).

           After the last day of the third cycle, the participant will have four nights with 8
           hours of sleep per night. The participant will be able to leave the research center in
           the morning after the 18th night.

           During each of the two 18-day stays in the hospital, participants will wear an
           actigraphy watch on all study days, which will help to evaluate sleep and measure the
           light level exposure. The participant will also have two blood draws obtained by a
           simple needle stick on intermittent days. Additionally, during these 24-hour periods,
           the study team will be collecting sleep recording data (using a polysomnography device
           over a 24-hour period). Finally, the study team will collect urine samples over the
           course of this protocol.

           Blood pressure will be measured at frequent intervals through the study. Computerized
           performance tests will be conducted at frequent intervals through the study. One of the
           tests involves measurement of reaction time by having participants press a button on a
           little box. In another performance test the study team will ask the participant to press
           the right or left mouse button depending on whether the word on the computer screen is
           printed in the same color or in a different color; this should be done as quickly and as
           accurately as possible. In addition, we will ask participants to rate well-being at
           frequent intervals throughout the stay in the Clinical Research Center.

           On several days during the stay in the Clinical Research Center, the investigators will
           test the perception of pain. During pain testing, the participant will remain in a
           comfortable chair throughout the testing session. The testing will consist of measures
           of pain threshold (first feeling of the sensation of pain to a heat or mechanical
           stimulus), pain tolerance (when the pain sensation feels intolerable), and pain
           modulation (how the central nervous system can change the perception of pain).

        4. Monitoring/Follow-Up Procedures. For this research study, the monitoring/follow-up
           procedures include meeting with one of the lead members of the study team on the last
           day of each of the 18-day protocols. During this time, a study team member will discuss
           the participant's study experience and will give the opportunity to ask any questions
           concerning the study.
    

Intervention name(s): Insomnia symptom induction
Intervention type(s): Behavioral
Intervention description(s): Several nights during the 18-day stay will be disrupted, such that we delay sleep onset, advance sleep off set, and the sleep period will be disrupted by frequent nighttime awakenings.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Basic Science