Melatonin improves sleep-wake patterns in psychomotor retarded children.

Five children with severe psychomotor retardation (mean age 8.2+/-3.6 years) and irregular sleep-wake patterns underwent 1 week of wrist actigraphic monitoring before and after treatment with 3 mg melatonin. Three underwent multiple measurements of urinary sulfatoxymelatonin levels. Urine sulfatoxymelatonin levels were abnormally low, without any significant day/night differences. Melatonin treatment increased nighttime sleep from 5.9+/-0.8 to 7.3+/-0.5 hours (paired t test, P<0.01) and sleep efficiency from 69.3%+/-6.2% to 88.3%+/-2.3% (P<0.01). Daytime sleep decreased from 3.2+/- 1.2 to 1.7+/-1.2 hours (P<0.05). Thus, no change in 24-hour total sleep time (9.1+/-1.5 vs. 9.0+/-1.6 hours) occurred. Administration of 3 mg melatonin to five severely psychomotor retarded children resulted in a significant improvement in their sleep-wake patterns.