Polysomnographic study of the effect of melatonin on sleep in elderly patients with chronic primary insomnia

The effect of 3-mg melatonin capsules p.o. on sleep in ten elderly patients suffering from chronic primary insomnia was assessed by polysomnographic r ecordings. In general, melatonin significantly reduced wake time after slee p onset and increased total sleep time and sleep efficiency during the 2-we ek treatment period. In five of the ten patients treated with melatonin, th e increase in total sleep time was clinically significant. Side effects wer e absent during the period of drug administration. A slight increase of pow er density in the delta and the theta regions was found during the early ph ase (i.e. nights 4-5) of melatonin administration, whereas the opposite cha nges were observed at a late phase of treatment (i.e, nights 15-16). No str ict correlation was found between prier 6-sulphatoxymelatonin levels in uri ne and subsequent sleep improvement after receiving melatonin. Our results further support the proposal that melatonin is beneficial for sleep disturb ances in elderly insomniacs. (C) 1999 Elsevier Science Ireland Ltd. All rig hts reserved.