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The Role of Melatonin in Sleep and Psychiatric Disorders
Could melatonin—an over-the-counter supplement—help people with psychiatric disorders by balancing their circadian rhythms? Read on to find out.
Melatonin is a common over-the-counter supplement that some have claimed can help everything from cardiovascular disease to cancer. This is partially due to its discovery as an antioxidant and partially due to (I suspect) wishful thinking.
Melatonin is more credibly known as a supplement that aids in regulating the sleep-wake cycle (circadian rhythm). This regulation may help people with sleep disorders and as many people with psychiatric illnesses have problems with sleep. Its application in psychiatric illnesses is being considered.
Melatonin is actually a natural chemical and the main hormone synthesized and secreted by the pineal gland. Melatonin is secreted at night (about 2 hours before sleep) and works as a circadian rhythm regulator with its peak concentration occurring at about 3-4 a.m. Melatonin secretion appears to open a “sleep window” wherein sleep is likely as the body is triggered into believing it is night.
Sleep and Psychiatric Disorders
It has been reported that 80 percent of patients with depression suffer from poor-quality sleep and sleep changes can often exacerbate or signal a shift in mood (such as transitioning into mania). Some even consider bipolar disorder to be a circadian rhythm disorder outright. There is also some evidence that there is genetic overlap between mood disorders and circadian rhythm disruption.
Sleep disturbances, of course, can be compounded by medication side effects. Changes in the amount and timing of melatonin secretion have been seen in patients with mood disorders, but it is difficult to separate whether this effect is occurring due to the mood disorder, the medication or both.
Melatonin as a Medication
Exogenous melatonin (i.e., externally consumed) has shown some use in reducing mood disorder symptoms and, in fact, a novel antidepressant (agomelatine) that works on the melatonergic and serotonergic systems has been formulated. In addition to antidepressant effects, agomelatine has been shown to promote beneficial sleep changes with fewer problems of next day sedation. Agomelatine, unfortunately, is not available in the United States.
Melatonin Side Effects
Melatonin appears to be safe in the short-term but no long-term data is available outside of case reports wherein melatonin has been used safely for years. Melatonin may increase next day sedation, vivid dreams or nightmares, however. It is possible that melatonin may disrupt other hormones.
Melatonin does not cause weight gain and, in fact, may help prevent metabolic syndrome illnesses, as well as have a beneficial effect on thrombus growth, cholesterol levels and blood pressure. Considering the propensity for some psychiatric medications to cause problems in these areas, the counterbalancing effect of melatonin is of interest to researchers.
Choosing to use melatonin should always be a decision made between patient and doctor as even though it is an over-the-counter medication, it is still a part of the treatment plan that the doctor needs to know about. One should also remember that as an over-the-counter supplement, the sourcing of melatonin is questionable as it does not fall under the strict regulations that govern pharmaceuticals.
Dosage and timing of melatonin usage plays a role in its effectiveness. It is suggested that 1-3 mg taken 3-4 hours before bedtime can help with delayed sleep while a higher dose of 3-9 mg taken 1-1.5 hours before bedtime can help with jetlag or primary insomnia. Dosages will vary, however, so it’s critical to discuss it with your doctor.
For facts referenced in this article, please see The Role of Melatonin in the Circadian Rhythm Sleep-Wake Cycle in Psychiatric Times.