Investigating the potential link between lunar cycle and multiple sclerosis relapses: a call for further studies

Multiple sclerosis (MS) is a debilitating disease that causes inflammation of the central nervous system, resulting in myelin damage and axon degeneration. Although the cause of MS remains unknown, various factors such as sex, latitude, sun exposure, serum vitamin D levels, Epstein Barr Virus infection, diet, microbiota and ethnicity are being studied for their potential roles in the development of the disease. While chronobiological factors such as circadian rhythm and seasonality have been explored for their potential influence on the onset, exacerbation, and/or relapses of MS, the potential influence of the lunar cycle on MS has yet to be studied. Therefore, the authors of this letter call for future studies to investigate the possible effects of the lunar cycle on MS activity and course, given evidence suggesting that the lunar cycle may affect sleep, fatigue, melatonin secretion, and mood state in humans. A deeper understanding of the chronobiology of MS could have practical implications for the development of chronotherapeutic strategies and the prevention or mitigation of MS relapses, potentially improving the quality of life of MS patients.