IRCT2014060717993N1 IRCT 2014-11-04 Research Department of Kashan University of Medical Sciences The effect of probiotic capsule supplementation on severity depression The effect of probiotic capsule supplementation on severity depression among patients with major depressive disorder under treatment with citalopram 2014-07-01 anticipated 40 Complete https://irct.ir/trial/16421 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: Patients will be randomly assigned into two groups. A randomization list will be generated from 1 to 40 by a random number generator (https://stattrek.com/statistics/random-number-generator.aspx) and patients will be randomly assigned into each intervention group by their numbers. The block randomization technique with 1:1 ratio will be used to achieve balanced group sizes, Blinding description: Randomization and allocation will be concealed from the researchers and participants until the final analyses are completed. Another person at the Clinic, who is not involved in the trial and not aware of random sequences, will assign the participants to the numbered bottles of drugs. Supplements and placebos are in the same packaging at the Tak Gen Zist pharmaceutical company. Only the code is written on the packages. Patients and researcher will not know the type of intervention. After analyzing the data, pocket codes will be decoded. Participants and investigators/the assessors of the outcomes are unaware of the study groups. 3 Depression. Intervention 1: Multi species probiotic capsules containing Lactobacillus acidophilus 2× 109 CFU, Lactobacillus casei 2× 109 CFU, Bifidbacterium bifidum 2 × 109 CFU. Intervention 2: Control group: Placebo capsule, daily, for 8 weeks. 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 Undecided - It is not yet known if there will be a plan to make this available