IRCT20141209020258N189 IRCT 2023-09-25 Arak University of Medical Sciences The effect of melatonin in the treatment of delirium in critically ill patients admitted to the intensive care unit The effect of melatonin in the treatment of delirium in critically ill patients admitted to the intensive care unit 2023-09-23 anticipated 80 Complete https://irct.ir/trial/72502 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: Patients will be allocated into 2 groups using a permuted balanced block randomization method with the size of blocks 4. Random sequence will be generated by an epidemiologist by running an online program in sealed envelope website (https://www.sealedenvelope.com/). Random chain concealment is done by opaque envelope method, Blinding description: In this study, the supervisor knows about the grouping and prescribes the drugs for the patients, and the interns do not know about the prescribed drugs, and the follow-up of the patients is with the interns, and the analyst does not know about the grouping, and as a result, the study will be double-blind. 3 Delirium. Intervention 1: Intervention group 1: Patients in this group will receive 3 mg of melatonin at night for 5 days. Intervention 2: Intervention group 2: The patients in this group will receive haloperidol (Caspian Tahind Pharmaceutical Company, Iran) at a dose of 2.5 mg intramuscularly every 6 hours. If necessary, up to 40 mg per day can be prescribed, and if delirium is not controlled with this dose, other drugs are used and the patient is excluded from the study. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is There is no more information.