Objective: To investigate the effect of melatonin treatment on health status and sleep in children with idiopathic sleep-onset insomnia.
Method: A randomized, double-blind, placebo-controlled trial was conducted in a Dutch sleep center, involving 62 children, 6 to 12 years of age, who suffered more than 1 year from idiopathic chronic sleep-onset insomnia. Patients received either 5 mg melatonin or placebo at 7 pm. The study consisted of a 1-week baseline period, followed by a 4-week treatment. Health status was measured with the RAND General Health Rating Index (RAND-GHRI) and Functional Status II (FS-II) questionnaires. Lights-off time, sleep onset, and wake-up time were recorded in a diary, and endogenous dim light melatonin onset was measured in saliva.
Results: The total scores of the RAND-GHRI and FS-II improved significantly more during melatonin treatment compared to placebo. The magnitude of change was much higher in the melatonin group than in the placebo group, with standardized response means for the RAND-GHRI of 0.69 versus 0.07 and for the FS-II of 1.61 versus 0.64. Melatonin treatment also significantly advanced sleep onset by 57 minutes, sleep offset by 9 minutes, and melatonin onset by 82 minutes, and decreased sleep latency by 17 minutes. Lights-off time and total sleep time did not change.
Conclusions: Melatonin improves health status and advances the sleep-wake rhythm in children with idiopathic chronic sleep-onset insomnia.