- Children are admitted to the NIH Clinical Center for 2-3 nights for melatonin treatment. They take a single dose of melatonin or placebo tablet at bedtime. During the daytime, EEG electrodes are placed to track eye movements. Between 7 PM and 7 AM serial blood samples are collected to measure melatonin levels. A parent rates the child s behavior and mood as described for the bright light study.