Objective: To evaluate the efficacy and safety of melatonin for the treatment of insomnia in pediatric patients with attention-deficit/hyperactivity disorder (ADHD).
Data sources: Literature was accessed through MEDLINE (1948-August 2009), EMBASE (1950-August 2009), and Scopus (1960-August 2009) using the terms melatonin, attention-deficit/hyperactivity disorder (ADHD), pediatric, insomnia, sleep disorder, and sleep. In addition, reference citations from publications identified were reviewed for relevant information.
Study selection and data extraction: All English-language articles and human studies were identified and evaluated. Results from all identified randomized trials (n = 5), safety studies (n = 1), long-term follow-up studies (n = 1), post hoc retrospective analyses (n = 1), meta-analyses (n = 2), review articles (n = 9), and letters (n = 1) were summarized.
Data synthesis: Pediatric insomnia is prevalent in children with ADHD and impacts academic performance, social functioning, overall health, and family life. First-line therapy includes ruling out differential diagnoses, optimizing ADHD stimulant treatment, and initiating good sleep hygiene and behavioral therapy. Adjuvant pharmacotherapy is then an option and melatonin is often prescribed. Melatonin regulates circadian rhythm sleep disorders such as sleep-onset insomnia (SOI) in children with ADHD. Four studies in children with ADHD and insomnia showed improvement in sleep onset and sleep latency. Studies included children 6-14 years old and melatonin doses ranged from 3 to 6 mg administered within a few hours of a scheduled bedtime. In all studies, adverse events were transient and mild. The available melatonin studies are limited by small size and short duration; variable SOI criteria, ADHD criteria, and treatment assessments; and lack of generalizability.
Conclusions: Available data suggest that melatonin is a well-tolerated and efficacious treatment option for pediatric patients with chronic SOI and ADHD. Regulated melatonin products and larger, well-designed trials to establish optimal dosing regimens and long-term safety are needed.