Conditions: Insomnia Blindness Daytime Sleepiness
Keywords: melatonin sleep blindness blind individuals
Allocation: NON_RANDOMIZED | Intervention model: FACTORIAL
Enrollment: 59
Healthy volunteers: no

Brief summary:
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.

Detailed description:

Arms:
arm 1: None arm 2: Subjects will be administered melatonin. arm 3: None arm 4: None arm 5: Optional longitudinal study, an extension of the first study stage, for subjects whose rhythms are not clearly free-running.

Interventions: intervention 1: Melatonin intervention 2: Regular Sleep Schedule intervention 3: Light
Intervention descriptions: intervention 1: Melatonin will be administered under FDA IND #26,318, doses between 0.025 mg and 20 mg. intervention 2: Subjects will maintain a regular sleep schedule of their choosing. intervention 3: Subjects will be exposed to light.

Protocol document: