Melatonin Fails to Improve Sleep in Alzheimer’s Disease

Abstract & Commentary

Source: Singer C, et al. A multicenter placebo-controlled trial of melatonin for sleep disturbance in Alzheimer’s disease. Sleep. 2003;26:893-901.

There are considerable anecdotal data suggesting that melatonin may improve sleep. About half of patients with Alzheimer’s disease (AD) experience some form of sleep disruption ranging from night-time awakenings to complete reversal of the diurnal sleep/wake cycle. This may further impair cognitive difficulties. Singer and colleagues carried out a trial of 2 sustained-release doses of melatonin—one moderately high dose of 10 mg and one moderately low dose of 2.5 mg. These were compared to placebo in 157 individual AD patients with sleep disruption who were treated for 2 months. Singer et al, unfortunately, found no significant improvement in objective measures of sleep. Those included sleep duration, sleep maintenance, and day/night sleep ratio.

Commentary

These results provide no encouragement for the use of melatonin for sleep disturbance in AD. This is a major clinical problem. At present, the only agents that have been shown to demonstrate some efficacy are more conventional sleep-inducing medications. — M. Flint Beal

Dr. Beal, Professor and Chairman; Department of Neurology; Cornell University Medical College New York, NY, is Editor of Neurology Alert.