Melatonin Effects in Methylphenidate Treated Children with Attention Deficit Hyperactivity Disorder: A Randomized Double Blind Clinical Trial

Objective: The aim of this study was to determine melatonin effects on sleep patterns, symptoms of hyperactivity and attention deficiency in children with attention-deficit hyperactivity disorder (ADHD).Methods: Children with age range of 7-12 years who had a combined form of ADHD were randomly divided in to 2 groups according to gender blocks. One group took melatonin (3 or 6mg) combined with methylphenidate (Ritalin) (1mg/kg), and the other group took placebo combined with methylphenidate (1mg/kg). ADHD rating scale and sleep patterns questionnaires were completed. Research hypotheses were assessed at the baseline, the second, fourth and eighth weeks after the treatment.Results: The mean sleep latency and total sleep disturbance scores were reduced in melatonin group, while the scores increased in the placebo group (p≥0.05). Data analysis, using ANOVA with repeated measures, did not show any statistically significant differences between the two groups in ADHD scores.Conclusion: Administration of melatonin along with methylphenidate can partially improve symptoms of sleep disturbance. However, it does not seem to reduce attention deficiency and hyperactivity behavior of children with ADHD.