Exploring Blood Plasma Metabolomics: Unraveling the Metabolic Landscape in Treatment-Resistant Adolescent Depression

Inclusion criteria

FEDN-MDD：

• Age 12-18 years
• Meet the diagnostic criteria for MDD according to the DSM-5
• First-episode and drug-naive
• HAMD-17 score > 17

TRD:

• Age 12-18 years
• Meet the diagnostic criteria for MDD according to the DSM-5
• HAMD-17 score > 13
• Currently or previously taking a standard therapeutic dose of antidepressant for at least 6 weeks, and they had at least one historical failure to an antidepressant (reduction in depressive symptoms <50%)

HC:

• age 12-18 years
• HAMD-17 score < 7
• HCs without a personal history of a mental illness or family history in a first-degree relative

Exclusion criteria

FEDN-MDD、TRD：

• the presence or past history of severe medical, neurological or psychiatric disorders (other than MDD in patients)
• anxiety comorbidity was not considered an exclusion criterion provided that MDD was the main diagnosis and the primary reason for seeking assistance
• substance abuse, head trauma, or loss of consciousness
• Chronic physical diseases that significantly affect peripheral metabolism or neurological function
• Pregnant and lactating women

HC:

• the presence or past history of severe medical, neurological or psychiatric disorders
• substance abuse, head trauma, or loss of consciousness
• Chronic physical diseases that significantly affect peripheral metabolism or neurological function
• Pregnant and lactating women