Parkinson's disease (PD) is the second most important neurodegenerative disease that affects
about 2% of the population over 60 years of age. About 40% of the Mexican population with PD
suffer from sleep disorders, which has been linked to a deregulation of the circadian cycle
and therefore of the clock genes. Melatonin is a hormone produced by the pineal gland that
regulates the sleep-wake cycle, at pharmacological doses, it is used to decrease sleep
disorders; it is suggested that is used could also normalize the levels of the clock genes
expression. In rats with PD, a decrease in clock genes levels has been observed, which are
restored by administering melatonin. The aim of the study is to evaluate the effect of
melatonin on the expression of the PER1 and BMAL1 clock genes in patients with PD during 12
months. A controlled, double-blind, randomized clinical trial will be carried out in patients
with a diagnosis of PD. A survey will be applied in order to know the course of the disease
and two more tests to rule out some sleep disorder, at the beginning of the study, at the 6th
month and at the 12th month. A blood sample (approximately 15 ml) will be taken every 3
months for a year. By random assignment, the participant will be given Melatonin or placebo,
which should be taken every day in the morning and evening after meals for one year.