Attention-deficit/hyperactivity disorder (ADHD) is one of the most common psychiatric disorders in childhood. Around 25-50% of these children suffered from some kind of sleep disorder especially with chronic form of insomnia. Nowadays, we know that there is a noticeable relationship between ADHD and sleep disorders and by improving these children's sleep, not only the daily functions of them improve, but also the symptoms of ADHD maybe become better. This research evaluates the effects of melatonin on improvement of Sleep quality in children with ADHD whom received Ritalin

Participants included 22 children suffered ADHD and concomitant sleep problems patients who underwent melatonin prescription and placebo at night in two sequencial periods. The effects of the melatonin were compared with placebo on the sleep problem improvements in each one.

Although sleep onset, total sleep time and sleep quality advanced with melatonin, wake up time and the time to go to bed had not significant difference between the melatonin and placebo group. In addition, there were significant effects on attention, hyper activity index and impulsivity of the patients in the melatonin group.

Melatonin advanced circadian rhythms of sleep-wake and not only enhanced total time asleep in children with ADHD and chronic sleep onset insomnia, but also can improve the quality of life of these patients.