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Effects of Season on Melatonin Secretion in Healthy Men and Women and Patients With Seasonal Affective Disorder

NCT00001485 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 116

Last updated 2008-03-04

No results posted yet for this study

Summary

As the seasons change during the course of the year, many animals show major changes in their behavior and physiology. Many of these changes are triggered by changes in the length of time each night that the pineal gland produces the hormone melatonin. Melatonin is produced for a longer time in winter when nights are long, than in summer when nights are short.

Some researchers believe that melatonin may play a similar role in how season effects mood of patients with seasonal affective disorder. Seasonal affective disorder (SAD) or mood disorder with seasonal pattern is a condition where the normal biorhythm is disturbed during a season, especially autumn-winter. Patients may begin experiencing or experience worsening of depressive symptoms. Patients complain of being constantly tired, craving sugary foods, overeating, and over sleeping.

Researchers have collected some preliminary data showing that the duration of nighttime melatonin secretion increases in winter and decreases in summer in healthy women, but not in healthy men. However, men diagnosed with SAD have shown longer duration of melatonin secretion in the winter, similar to the duration seen in healthy women. If these early findings are confirmed it may explain why SAD is more common in women than in men.

The purpose of this study is to continue researching the differences in melatonin secretion over the seasons in healthy men and women, and to determine how these findings may apply to patients with SAD.

Conditions

  • Seasonal Affective Disorder

Sponsors & Collaborators

  • National Institute of Mental Health (NIMH)

    lead NIH

Eligibility

Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
1995-06-30
Completion
2000-04-30

Countries

  • United States

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00001485 on ClinicalTrials.gov