Melatonin for Chronic Back Pain (The MOCHA trial): Study Protocol for a Randomized, Double-Blind, Placebo-Controlled Trial

Background: Chronic back pain remains a leading cause of disablity worldwide with high societal and healthcare costs and limited effective treatment options. More than 50% of people with chronic back pain also report insomnia symptoms. Melatonin, primarily known for its use in treating insomnia and jetlag, has shown promising effects as a pain medication in chronic non-musculoskeletal pain conditions. We aim to determine the efficacy of 6 weeks of melatonin compared with placebo in reducing average pain intensity in patients with chronic disabling back pain. Method: The Melatonin for Chronic Back Pain (MOCHA) trial is a 1:1 randomized, placebo-controlled, double-blind, superiority trial including 220 patients with chronic disabling back pain randomized to either 10 mg melatonin daily for 6 weeks or an identically looking placebo tablet. The primary outcome is the between group difference in change in average pain intensity during the last 7 days from baseline to 6 weeks. Secondary outcomes include insomnia severity, back pain-related disability, global perceived effect, physical and mental health and pain sensitivity. Exploratory outcomes are physiological sleep metrics assessed with ear electroencephalography (EEG). Discussion: This trial evaluates the efficacy of melatonin, an inexpensive and widely available intervention that could potentially reduce pain and sleep problems in a population with few effective treatment options available. Trial registration: CTIS: EU-CT 2023-503530-41-00 (Registered on March 4^th 2024) ClinicalTrials.gov: NCT06476392 (Registered on June 20^th 2024)