Circadian Phase Assessments at Home
Condition: Healthy Controls; Delayed Sleep Phase
Study type: Interventional

Summary: 
      An estimated 23 million Americans, including adolescents and the elderly, suffer from
      circadian rhythm sleep disorders, such as delayed sleep phase disorder, advanced sleep phase
      disorder and winter depression. These conditions are characterized by persistent insomnia
      and/or excessive daytime sleepiness, impaired performance, reduced well being and lower
      quality of life. The negative symptoms result from a misalignment between the timing of sleep
      and the internal circadian clock. Clinical research has demonstrated that circadian rhythm
      sleep disorders are most effectively diagnosed (differentiated from other causes of insomnia)
      and treated if each individual patient's circadian phase is known. The timing of the master
      internal circadian clock is most reliably measured from the onset of the endogenous circadian
      rhythm of melatonin, a neuroendocrine hormone, as measured in dim light (dim light melatonin
      onset, or "DLMO"). However to date the reliable and valid assessment of the DLMO is limited
      to the research laboratory setting.

      This study is to test a streamlined procedure for the accurate assessment of circadian phase
      (DLMO) outside of the laboratory that will provide clinicians and researchers with a novel
      diagnostic and research tool. In this way the underlying neurobiological cause of a patient's
      insomnia and/or circadian rhythm disorder can more readily be diagnosed and treated.

      Specific Aim 1 is to validate procedures for at-home circadian phase assessment in a sample
      of healthy people. Validation will occur by (1) objectively measuring compliance to the
      at-home procedures and (2) comparing DLMOs collected at home to DLMOs collected in the
      laboratory, in a within-subjects counterbalanced design. Specific Aim 2 is to validate the
      same at home procedures in patients with delayed sleep phase disorder. Specific Aim 3 is to
      conduct rigorous analyses to inform future users which subject characteristics and light
      levels predict (1) compliance to the at home procedures and (2) valid at-home DLMOs.

      The results of this 3 year study will have substantial implications for the translation of
      basic and clinical research to the community: (1) the diagnosis and treatment of insomnia and
      circadian rhythm sleep disorders will be significantly enhanced, thus improving public health
      and safety, mood and quality of life, (2) community participation in research will be
      improved, particularly in vulnerable and under represented populations, thus increasing
      scientific knowledge and (3) research and clinical costs will be substantially reduced.
    


Intervention name(s): At home saliva sampling
Intervention type(s): Behavioral
Intervention description(s): Saliva samples taken every half an hour in evening before bedtime.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Diagnostic