Melatonin for Circadian Sleep Disorders in the Blind

Study Overview
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Brief Summary
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This research project consists of a three part study with five embedded sub studies. The first study phase identifies body rhythms of sleepiness/wakefulness and of melatonin levels for each subject (including sub-study 1). The second study phase identifies the optimum dose and timing of melatonin for regulating each individual's 24-hour sleep/waking cycle (including sub-study 2). The third study phase introduces a new independent variable, light (including sub-studies 3 and 4). Sub-study 5 is an optional longitudinal study. Sub-study 1 looks at how keeping a regular sleep schedule affects the body's natural rhythm. Sub-study 2 looks at how individuals metabolize melatonin. Sub-study 3 tests how individuals' endogenous melatonin production responds to bright outdoor light and Sub-study 4 tests a previous finding that artificial bright light exposed daily behind the knee can regulate the body clock. Sub-study 5 is an optional longitudinal study, an extension of the first study stage, for subjects whose rhythms are not clearly free-running.

Official Title
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Melatonin for Circadian Sleep Disorders in the Blind

Conditions
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Insomnia, Blindness, Daytime Sleepiness

Intervention / Treatment
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* Drug: Melatonin
* Behavioral: Regular Sleep Schedule
* Behavioral: Light


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: blindness for at least one year, verified by an ophthalmologic exam ability to comply with the requirements of the experimental protocol competency to sign informed consent Exclusion criteria (as determined by medical history and/or physical examination): abnormal heart, liver or kidney function a current Axis I psychiatric or substance abuse disorder according to the DSM-IV Manual possibly external demands that limit the ability to maintain a regular schedule (e.g., night shift work) sexually active female subjects of child-bearing potential will be asked to avoid pregnancy using accepted methods and will be notified that the effects of melatonin on a fetus are not known (we will ask subjects monthly if they are pregnant or trying to become pregnant) if a subject reports she is pregnant or is trying to become pregnant anytime during her study participation, any study medications (melatonin or placebo) will be immediately withdrawn and the subject will be excluded from the study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Factorial Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Baseline<br> | |
| Experimental: Melatonin<br>Subjects will be administered melatonin. | Drug: Melatonin<br>* Melatonin will be administered under FDA IND #26,318, doses between 0.025 mg and 20 mg.<br>|
| Experimental: Light<br> | Behavioral: Light<br>* Subjects will be exposed to light.<br>|
| Experimental: Regular Sleep Schedule<br> | Behavioral: Regular Sleep Schedule<br>* Subjects will maintain a regular sleep schedule of their choosing.<br>|
| No Intervention: Longitudinal Monitoring<br>Optional longitudinal study, an extension of the first study stage, for subjects whose rhythms are not clearly free-running. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Treatment Effects on Circadian Phase Will be Assessed During Each Trial by Measuring the Timing of Endogenous Melatonin Secretion. |  | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Treatment Effects on Sleep and Alertness Will be Assessed by Daily Diaries and Daily Wrist Actigraphic Monitoring. Subjective Benefits Will be Assessed With Daily Ratings of Alertness and Vigor. |  | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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melatonin, sleep, blindness, blind individuals