What will we do: We will measure the patient's own timing of release of melatonin and provide a dose of melatonin at a standard time at night (8PM) to test the effects on the electrical activity of sleep over a three month period. In addition to brain electrical activity, we will record sleep behavioral data and physical activity using activity monitors worn by the patients. Patient subjects in this study will be studied twice during the three month period in three day inpatient visits where they will undergo video monitoring and sampling of brain electrical activity using pasted electrodes ("EEG"), hourly saliva sampling for one day, and participate in behavioral testing.