Melatonin Studies of Totally Blind Children

Unique provision in the American Recovery and Reinvestment Act prevented approval of second year no-cost-extension in which completion of analyses were planned.

The purpose of this study is to learn more about abnormal body rhythms in blind boys and girls that keep them from falling asleep at bed-time or cause them difficulty staying alert during the day. The investigators hope to learn if there are any differences between the body rhythms of girls and boys. The investigators also want to investigate whether age or puberty have an effect on body rhythms.

Subjects will be asked to collect saliva samples in their home hourly throughout the daytime, approximately every 2 weeks. Subjects may be monitored for up to a year, after which they will be discontinued from the study. If subjects are found to be naturally entrained to the 24-hour day, they will be monitored longitudinally for changes. Subjects will be discontinued after their monitoring period is over or after an entrained status has been confirmed. While no specific time commitment is required, we hope most subjects will participant for 4 months - 2 years.

One 0.5 mg tablet of melatonin will be taken by subjects who are free-running and willing to enter the intervention phase of the study. These subjects will take melatonin until entrainment status is confirmed or throughout the duration of the study.

To Test for a Proportional Gender Difference in Circadian Status (Free-running Versus Entrained) in Blind Children and in Adolescents, a Chi-square Test of Significance Will be Used for Each Age Group.

To Test for a Proportional Difference in Circadian Status (Free-running Versus Entrained) Between Pre and Post- Pubertal Males in Blind Boys and Young Men, a Chi-square Test of Significance Will be Used for Each Age Group.

To Determine the Efficacy of Melatonin Treatment in Entraining Blind Free-running Children and Young Adults, a Binomial Test Will be Used.

Inclusion Criteria: Totally blind Between 5-8 yrs or 17-20 yrs of age Exclusion Criteria: Pregnancy Light perception Low melatonin production Taking melatonin Co-morbid medical disorders (such as seizure disorders)