Study aim: Improvement in depression and antioxidant status in patients with major depression Design: In this clinical trial with a control group, with parallel groups, double-blind, randomized, phase 3, 60 patients with major depression who meet the inclusion criteria and are referred to Shahid Zare Hospital of Mazandaran University of Medical Sciences are selected. Participants are randomly divided into intervention and control groups using random blocks and a code is assigned to each participant. Settings and conduct: This study will be done by referring to the Specialty Shahid Zare Hospital of Mazandaran University of Medical Sciences. The intervention and control group will receive 200 mg of Gallic acid or placebo daily for 2 months, respectively. Each person will complete a consent form, a personal information questionnaire, physical activity, and 24-hour diet recall. Fasting blood samples were also collected at the beginning and end of the study in 10 ml from participants. In this study, participants will be randomly divided into two groups (30 persons) through the table of random numbers. Participants/Inclusion and exclusion criteria: Inclusion criteria: willingness to cooperate, major depressive, age 18- 55, no change in treatment and medications in the last 2 months Exclusion Criteria: pregnancy and lactation, patients with severe renal and hepatic impairment, alcohol consumption Intervention groups: Intervention group: the group receiving Gallic acid (200mg daily) Control group: placebo group Main outcome variables: Depression score, oxidative stress indices