Inversion of Melatonin Circadian Rhythm in Chronic Alcoholic Patients during Withdrawal: Preliminary Study on Seven Patients

Aims: The inversion of melatonin circadian rhythm secretion in some alcoholics during both intake and acute withdrawal has been widely reported. In the same way, what happens to this inversion when these patients are in long-term withdrawal is not known. To document this abnormality in alcoholics after withdrawal we investigated melatonin secretion observed during chronic alcoholization and after withdrawal. Methods: We measured the urinary 6-sulfatoxymelatonin (6SM) (6SM/creatinine ratio), main metabolite of the hormone, in two fractions, one diurnal and the other nocturnal, in seven alcohol-dependent patients presenting with this abnormality during alcoholization at two times: in acute withdrawal phase (under benzodiazepines) and 15 days after beginning of withdrawal (free of any psychotropic treatment). Results: Our results show that this reversed rhythm of melatonin secretion as seen by the diurnal excretion of 6SM (6SM/creatinine ratio) persists during acute withdrawal in more than half of the patients and is still present 15 days after withdrawal in three patients. Conclusion: It is remarkable that the inversion of the melatonin rhythms gets corrected in four out of seven patients after withdrawal. But, the circadian disorganization of melatonin secretion in three patients could underline a desynchronization in some alcoholic patients and may indicate more widespread circadian temporal structure disturbances in these patients.