The researchers believe the hormone melatonin may not only improve sleep but also diminish depression that has been exacerbated by sleep deprivation. Many patients starting on antidepressants such as Prozac (R) continue to suffer from insomnia during the three- to five-week period before the drug takes effect. Insomnia is one of the most common -- and debilitating -- symptoms of depression, which affects the lives of nearly 15 percent of the adult population.
Melatonin, a hormone that plays a vital role in setting the body's biological clock, has received widespread attention for its ability to induce sleep in individuals and to "reset" the body's circadian rhythms resulting from jet lag and other sleep disturbances.
The melatonin in the Northwestern study has undergone rigorous testing by the Food and Drug Administration to ensure its purity and safety for use in humans. Pharmacists at Northwestern Memorial Hospital will specially prepare the melatonin capsules for the study according to strict FDA guidelines to guarantee its uniform quality and potency. This process also will help the researchers determine the amount of melatonin required to restore normal sleep.
A recent Canadian study found that many pills labeled as melatonin in health food and drug stores either had limited amounts of melatonin in them or contained no melatonin at all.
To qualify for the Northwestern University study, volunteers must be between the ages of 18 and 65, have a current or suspected diagnosis of depression, have insomnia and have no chronic medical illness. In addition, individuals must be off antidepressant medications for at least two weeks before entering the study. Women must be post menopausal, sterilized or using reliable contraceptive methods other than abstinence alone.
Maria Caserta, M.D., associate professor of psychiatry and behavioral sciences and a researcher in the Asher Center for the Study and Treatment of Depressive Disorders at Northwestern, is principal investigator for the study. Co-investigators include Margarita L. Dubocovich, professor of molecular pharmacology; Howard Tushman, M.D., a resident physician in the department of psychiatry and behavioral sciences; and Monica I. Masana, research assistant professor of molecular pharmacology.
This study is funded by the Asher Center for the Study and Treatment of Depressive Disorders in the department of psychiatry and behavioral sciences at the Medical School and the Northwestern University Drug Discovery Program.