Here is the design of a clinical trial:

Official Title: Effect of Esketamine on Perioperative Depressive Symptoms in Patients Undergoing Major Surgery

Included conditions:
- Depressive Symptoms
- Esketamine
- Perioperative Complication
- Major Surgery

Study Armgroups:
- {'label': 'Esketamine', 'type': 'EXPERIMENTAL', 'interventionNames': ['Drug: Esketamine']}
- {'label': 'Placebo', 'type': 'PLACEBO_COMPARATOR', 'interventionNames': ['Drug: Normal saline']}

Interventions:
- {'type': 'DRUG', 'name': 'Esketamine', 'description': 'Esketamine will be administrated intravenously when suturing incision, with total dose of 0.2mg/kg and continuous infusion for 40 minutes.', 'armGroupLabels': ['Esketamine']}
- {'type': 'DRUG', 'name': 'Normal saline', 'description': 'Equivalent amount of normal saline will be administrated intravenously suturing incision.', 'armGroupLabels': ['Placebo']}

Primary Outcomes:
- {'measure': 'Depressive symptoms remission', 'description': 'Remission is defined as MADRS total score no more than 10', 'timeFrame': 'Postoperative 3-day'}

Please estimate the sample size based on the assumption: 
80% power, two-sided significance level of 0.05, 1 interim analysis, and a 10% attrition rate.
Sample size calculation
        It has been reported that the remission rate difference in the antidepressant effects between esketamine and ketamine was 3.8% in treatment-resistant depression patients.26 In the perioperative population with depressive symptoms, the remission rate was reported to be 23.1% in the ketamine group and 9.3% in the placebo group based on the PASSION study at our research site. We assumed that the remission rate in the esketamine group will be 19.3% and that in the placebo group will be 10%. A sample size of 506 participants will provide 80% power to show the difference between the esketamine group and the placebo group (with a ratio of 1:1), including 1 interim analysis by using a two-sided significance level of 0.05.27 With the consideration of a 10% attrition rate, the total sample size is planned to be 564.