Melatonin, antihistamines, and bright light therapy for insomnia
Q. What do you think about melatonin and valerian as treatments for insomnia?
A. Melatonin is a hormone produced in the body by the pineal gland in response to darkness and as a cue for sleep. Valerian is an herb promoted as a mild sedative. Both melatonin and valerian are sold as dietary supplements in the United States and are marketed as sleep aids. The National Institutes of Health’s June 2005 chronic insomnia state-of-the science conference statement did not recommend the use of melatonin or valerian for insomnia, based upon lack of evidence for either efficacy or safety.
Melatonin may have a role for other sleep disturbances, particularly circadian rhythm disorders and perhaps jet lag, but there is no good evidence that it is beneficial as a sleep-promoting medication for the treatment of insomnia. This is true for valerian as well. It may just be that the proper research has not been done yet; studies published to date have not been convincing. The bottom line is that I don’t recommend trying either of these supplements as a treatment for chronic insomnia.
Q. Are over-the-counter antihistamines effective sleep aids for insomnia?
A. Antihistamines, such as diphenhydramine (the active ingredient in products like Tylenol PM), are the most commonly used nonprescription treatments for chronic insomnia. However, there is no convincing evidence that these drugs are effective over time for chronic insomnia, and major concerns about their risks have emerged. Residual daytime sedation, compromised cognitive function (a particular concern in the elderly), constipation, and dry mouth are some of the adverse effects of antihistamines. For transient insomnia (just for a night or two) antihistamines may help, but they are not a solution for more persistent insomnia, and patients should not use them as such.
Q. Is bright-light therapy an effective treatment for insomnia?
A. Bright-light therapy has proven efficacy for people with circadian rhythm disorders. It involves sitting in front of a therapeutic bright-light box for about 20–60 minutes each day. To be maximally effective, the light should come from a fluorescent light box that delivers an intensity of 10,000 lux. It is important to position the light box according to your doctor’s instructions and to use it at the same time each day as consistently as possible. For so-called night owls, we aim to maximize their bright-light exposure early in the day, as soon as they wake up and get out of bed. We do the opposite for early birds with advanced sleep phase pattern. We use bright light in the evening to shift their circadian rhythm later.
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