Clinicians should measure dim light melatonin onset before treating patients with circadian rhythm sleep disorders, according to Dr. Henry Keijzer of the University Maastricht (the Netherlands) and his associates.
The test enables clinicians to assess patients’ individual circadian timing, the reviewers said. At least 17 of the 90 scientific studies they reviewed support the use of the test in this context, and it can be performed by collecting saliva at home if in-clinic testing is not feasible, they added.
Although patients are often told to take exogenous melatonin 1-2 hours before bedtime, this generalized approach can lead to adverse phase-shifting effects, the reviewers said (Sleep Med. Rev. 2014;18:333-9).
"Therefore, we believe that the use of melatonin in patients with chronic sleep problems should occur only after their baseline circadian timing information is known, and should be supervised by a health care professional who is familiar with melatonin and its phase-dependent effects," they wrote.
The authors expressed concern that "melatonin is increasingly recommended for patients with insomnia or used by such patients as an over-the-counter self-care medicine."
The investigators reported no funding sources or conflicts of interest.