Cognitive, health and psychosocial effects of melatonin and light therapy in childhood insomnia Double-blind placebo-controlled study

Introduction: To examine effects of melatonin and light therapy on cognitive, health and psychosocial outcomes in children with chronic sleep onset insomnia; and to disentangle direct effects from indirect effects through sleep improvement.

Methods: A randomized, double-blind placebo-controlled trial was conducted in which 84 children received melatonin treatment, placebo pills, or light therapy for three to four weeks, after a baseline period of one week. Daily sleep measures were obtained through actigraphy, and children completed cognitive tasks (simple reaction time, visuomotor control, working memory and selective attention) and parents and children completed questionnaires concerning health, mood, school functioning, behavioral and attention problems, at baseline and post-treatment. Regression analyses with bootstrapping were carried out to disentangle direct and indirect (i.e. through sleep) effects.

Results: Melatonin treatment improved health and light therapy decreased behavior problems. Although both treatments improved sleep, the treatment effects on health and behavior problems were not mediated by sleep.

Conclusions: Melatonin and light therapy improved chronic sleep onset problems in children, but fewer effects were found on cognitive, health and psychosocial functioning, and these effects were not mediated by sleep improvement.

Acknowledgements: Pharma Nord sponsored the melatonin and placebo tablets for the study, Physician Engineered Products offered the light devices with discount. Both companies were not involved in the study and report of the results.