Figures (4)  Tables (1)
    • Figure 1. 

      Integrated biological biotypes of depression and their underlying mechanistic pathways. (a) Immuno-metabolic/inflammatory biotype, where peripheral inflammation drives microglial activation, and shifts tryptophan metabolism toward neurotoxic kynurenine metabolites, reducing serotonin; (b) neural circuit/reward-cognitive biotype, characterized by disrupted prefrontal amygdala connectivity, blunted ventral striatum response, and impaired default mode executive network interactions; and (c) genomic/plasticity biotype, marked by genetic risk variants that impair neurotrophic signaling and synaptic plasticity. Each biotype maps to specific therapeutic strategies, anti-inflammatory/kynurenine modulators, circuit targeted neuromodulation, and plasticity enhancing agents, respectively, illustrating a mechanism-based framework for precision treatment in depression.

    • Figure 2. 

      The paradigm shifts toward precision drug development in depression. This framework illustrates the transition from empirical screening to a mechanism based approach across three stages: (a) human-anchored discovery, where large scale genomics (GWAS) and Mendelian randomization replace traditional animal models to identify causally valid targets; (b) mechanism tailored therapeutics, developing specific agents for distinct biotypes, such as anti-inflammatory biologics, rapid acting glutamatergic modulators, and microbiome interventions; and (c) next-generation evidence generation, utilizing biomarker enriched adaptive platform trials and digital endpoints to efficiently validate efficacy in specific patient subgroups.

    • Figure 3. 

      Mechanism-based clinical decision framework for precision treatment in depression.

    • Figure 4. 

      An integrated roadmap for a precision psychiatry ecosystem. This framework illustrates the translational pathway from; (a) discovery and validation, where multi-omics and digital data inform AI-driven biotype identification; to (b) adaptive platform trials, utilizing master protocols to dynamically assign patients to mechanism-based treatments; and finally to (c) AI enabled closed loop care, where real-world clinical outcomes continuously refine predictive models, creating a learning health system that bridges research and clinical practice.

    • CategoryKey approach/methodMain finding or contributionImplication for MDDRef.
      Multi-omics and
      causal inference
      Mitochondrial multi-omics integrationIdentified mitochondrial-related causal genes for MDDLinks cellular energetics to depression pathogenesis[74]
      Gut microbiome + metabolomicsRevealed bacterial/metabolic signatures in MDDSupports gut-brain axis as therapeutic target[75]
      Proteome-transcriptome integration (brain/blood)Prioritized causal genes for depressionEnables cross-tissue biomarker discovery[81]
      Single-nucleus ATAC-seqMapped chromatin accessibility in MDD-relevant cell typesIdentifies regulatory variants in excitatory neurons[82]
      Bulk and single-nucleus transcriptomicsConvergent synaptic dysregulation in excitatory neuronsHighlights shared molecular pathology across cohorts[83]
      Cross-disorder systems biology (MDD/PTSD)Shared and distinct molecular signatures across brain regionsSuggests transdiagnostic mechanisms[84]
      Two-sample Mendelian randomizationIL-6 and plasma proteins causally linked to MDDValidates immune-inflammatory pathway as causal[78,79]
      Digital phenotyping and AIGraph neural networks on fMRIDetected functional connectivity features of MDDOffers data-driven neuroimaging biomarkers[77]
      Survey of ML/DL in psychiatryReviewed AI applications in depression detection/treatmentMaps current landscape of computational psychiatry[50]
      Smartphone/wearable digital phenotypingDemonstrated feasibility of passive mood monitoringEnables real-time symptom tracking[50,85]
      Wearable sensors + ML modelingPredicted depression severity from behavioral dataSupports scalable screening tools[86,87]
      Retrospective mHealth analysisHighlighted challenges in data quality/predictionCalls for standardized digital biomarker validation[88]
      Novel therapeuticsPreclinical/clinical reviewKetamine may benefit TRD in Alzheimer's/elderlyExpands ketamine's applicability beyond typical TRD[89]
      fMRI + glutamate spectroscopyLinked S-ketamine's acute network effects to delayed glutamate changesClarifies mechanism of rapid-acting antidepressants[90]
      KOR antagonist (anticipant) in UCMS miceReversed stress-induced depressive behaviorsSupports kappa opioid system as drug target[91]
      Precision psychiatry and EHREHR-based stratificationShowed EHR can enable patient subtyping and treatment predictionBridges real-world data to precision care[92,93]
      Pharmacogenomics + CDS in EHRImplemented PGx-guided prescribing with clinical impactProves feasibility of genomic medicine in psychiatry[9496]
      Patient-centered care and equityDecision aids for depression/TRDImproved shared decision-making in RCTsEnhances patient autonomy in complex treatment choices[97,98]
      Conceptual frameworkArgues for 'person-centered' over purely biological precision psychiatryCalls for integrating lived experience[99]
      Health equity frameworksHighlight disparities in genomic/
      digital mental health access
      Urges inclusive design and intersectional research[100102]
      Detection and predictionDNA methylation risk scores (MRS)MRS significantly discriminated MDD cases from controlsEnhancing MDD prediction from PRS and environmental traits[103]
      Examine surrogate measures of insulin resistanceThree measures positively predicted incident MDD in a 9-year follow-up periodUseful for evaluating the risk of MDD among patients with metabolic pathology[104]
      Machine learning to identity multivariate MDD biomarkersMean accuracies for diagnostic classification ranged between 48.1% and 62.0%Improved predictive capability compared with univariate neuroimaging markers[105]
      Volatile organic compounds (VOCs) from breath76.8% accuracy to distinguish MDD patients from healthy controlsPromising for use of biomarkers in gas samples of human breath as a diagnostic measure[106]

      Table 1. 

      Recent advances in major depressive disorder research: multi-omics, digital phenotyping, and precision psychiatry approaches.