Cluster headaches are one-sided headaches that occur in cyclical patterns, often referred to as “clusters.” Periods of frequent attacks are called cluster periods and may last weeks or months, followed by remission phases that can last months or even years. Onset is usually sudden, and the pain is severe and unilateral, most often centered around one eye. Patients frequently describe the pain as excruciating, sometimes likened to a hot poker behind the eye. Attacks are commonly accompanied by redness, swelling, and excessive tearing on the affected side. The eyelid may droop, and the pupil may constrict. Migraine-like features such as nausea, sensitivity to light or sound, and aura can also occur.
During a cluster period, headaches often occur daily and may strike several times per day. Individual attacks typically last between 15 minutes and several hours and often occur at the same time each day. Unlike migraine sufferers, patients with cluster headaches tend to become restless during an attack and may pace or rock back and forth, as movement can feel soothing. Lying down often worsens the pain, so patients usually avoid it during an attack.
Research suggests that people with cluster headaches often have reduced nocturnal melatonin levels. A double-blind, placebo-controlled study published in Cephalalgia (1996;16:494–496) evaluated 20 patients with cluster headaches who were given either melatonin or a placebo at bedtime for two weeks. The melatonin dose used was 10 mg nightly. Patients receiving melatonin experienced fewer headaches and required less medication than those in the placebo group. After three to five days of treatment, about half of the patients in the melatonin group became headache-free until the supplement was discontinued.
Additional support for melatonin’s potential role comes from case reports published in Neurology (September 2003;61:865–866), which described three patients with idiopathic stabbing headaches who experienced relief with melatonin. The authors suggested starting with 3 mg at bedtime and gradually increasing the dose every few nights if needed, noting that higher doses had been used in some cases.
