Study Title: Research on the therapeutic effect and clinical indicators of XingpiJieyu formula in the treatment of severe liver depression and spleen deficiency type depression based on abnormal mitochondrial energy metabolism pathway

Purpose of the Study: (1) Application of XPJYF in the treatment of severe MDD patients for 8 weeks, detection of abnormal mitochondrial energy metabolism and biosynthesis, and exploration of biological markers for the therapeutic effect of XPJYF in the treatment of severe MDD with liver depression and spleen deficiency type. (2) Explore the biological indicators for predicting the antidepressant efficacy of XPJYF in the treatment of severe MDD patients and explore new pharmacological pathways for the combination of traditional Chinese and Western medicine in the treatment of MDD.

To evaluate whether adding Xingpi Jieyu Formula (a traditional Chinese herbal granule) to the standard antidepressant escitalopram improves symptoms in people with severe major depressive disorder (MDD) who also have a specific traditional Chinese medicine pattern called "Liver-Stagnation and Spleen-Deficiency."

Study Design:

100 patients with severe MDD (Liver-Stagnation and Spleen-Deficiency pattern) will be randomly assigned to one of two groups: Test group: Escitalopram + Xingpi Jieyu Formula, Control group: Escitalopram + placebo (identical granules with no active ingredient).

An additional 50 healthy volunteers will serve as a comparison group. Treatment duration: 8 weeks. Double-blind design: neither participants nor study doctors know who receives the real herbal formula or the placebo.

Data Collection Timepoints: Baseline (before treatment), Week 2, and Week 8 (end of treatment). At each timepoint, blood samples and clinical information (e.g., mood ratings, symptom scores) will be collected.

Main Measurements: Blood samples will be tested for markers of mitochondrial energy metabolism (using ELISA). Whole genome testing will be performed in 60 patients (from the MDD groups) and in all 30 healthy volunteers.

Inclusion Criteria: ① Outpatient/inpatient, aged 18-60, right-handed. ② The diagnosis of Western medicine meets the diagnostic criteria of DSM-5 for MDD, as well as the diagnostic criteria for depression and liver depression and spleen deficiency in the 2008 Guidelines for the Diagnosis and Treatment of Common Diseases in Traditional Chinese Medicine issued by the Chinese Society of Traditional Chinese Medicine HAMD-17 score ≥ 18 points, and HAMD-17 item 3 ≤ 2 points

Exclusion Criteria: ① DSM-5, with the exception of MDD, has any current or past diagnosis of Axis I mental disorders (MINI). Or it does not meet the diagnostic criteria for depression and liver depression and spleen deficiency syndrome in the "Diagnosis and Treatment Guidelines for Common Diseases in Traditional Chinese Medicine" issued by the Chinese Society of Traditional Chinese Medicine in 2008. ② Education years<5 years or IQ<90 points. ③ Suicide ideation or suicidal behavior (HAMD-17 item 3>2 points).

Possible Benefits: May offer a new treatment option for patients with severe depression who do not fully respond to standard antidepressants. May help identify blood markers that can predict which patients are most likely to benefit from adding traditional Chinese medicine to their treatment. May improve understanding of how traditional Chinese medicine affects cellular energy metabolism (mitochondria), potentially leading to better treatments for depression.

Risks and Safety: All study medications (escitalopram and Xingpi Jieyu Formula) are already approved for clinical use. Side effects are known and generally mild. Blood draws may cause temporary discomfort or bruising. Participants will be closely monitored by study doctors. If serious side effects occur, the study medication can be stopped and appropriate medical care will be provided. All personal information and test results will be kept confidential.

Study Location and Approval: This study is led by researchers at Peking University Sixth Hospital (and other collaborating centers) and has been approved by the Medical Ethics Committee.

Inclusion Criteria:

① Outpatient/inpatient, aged 18-60, right-handed

② The diagnosis of Western medicine meets the diagnostic criteria of DSM-5 for MDD, as well as the diagnostic criteria for depression and liver depression and spleen deficiency in the 2008 Guidelines for the Diagnosis and Treatment of Common Diseases in Traditional Chinese Medicine issued by the Chinese Society of Traditional Chinese Medicine HAMD-17 score ≥ 18 points, and HAMD-17 item 3 ≤ 2 points

Exclusion criteria：

• DSM-5, with the exception of MDD, has any current or past diagnosis of Axis I mental disorders (MINI). Or it does not meet the diagnostic criteria for depression and liver depression and spleen deficiency syndrome in the "Diagnosis and Treatment Guidelines for Common Diseases in Traditional Chinese Medicine" issued by the Chinese Society of Traditional Chinese Medicine in 2008 ② Education years<5 years or IQ<90 points ③ Suicide ideation or suicidal behavior (HAMD-17 item 3>2 points)