Fig. 1: Process pipeline for this study.

A Extraction of RNA from plasma exosomes and miRNA sequencing analysis. B Collection and process of multimodal MRI data. C Significant multimodal MRI patterns associated with miR-151a-3p expression were identified using the ‘MCCAR+jICA’ algorithm and input into an SVM model to classify individuals into MDD or HC groups. D After regulating the expression of miR-151a-3p in the ACC of mice using AAV, the behavioral changes and alterations in downstream gene expression in mice were investigated. miRNA microRNA, qRT-PCR quantitative reverse transcription–polymerase chain reaction, MCCAR+jICA multisite canonical correlation analysis with reference plus joint independent component analysis, SVM support vector machine, MDD major depressive disorder, HC healthy control, MFA multimodal feature abnormalities, ACC anterior cingulate cortex, AAV adeno-associated virus, NGS next generation sequencing. The Fig. 1 was created in BioRender. Liang, W. (2025) https://BioRender.com/s0uplic.