Convergent Lower Expression of Redox-Linked Stress-Adaptation and Synaptic-Plasticity Genes in Major Depressive Disorder Across Seven Postmortem dlPFC Cohorts

Major depressive disorder (MDD) has been linked to oxidative stress, mitochondrial dysfunction, and impaired neuronal plasticity, but the reproducibility of related transcriptomic alterations across postmortem brain cohorts remains uncertain. We performed a targeted cross-platform analysis of a prespecified 14-gene panel spanning antioxidant defense, mitochondrial-redox regulation, cellular stress responses, neurotrophic signaling, synaptic plasticity, and polyamine metabolism across seven postmortem dorsolateral prefrontal cortex cohorts comprising 146 MDD cases and 179 controls. Primary support required Fisher-combined evidence, Benjamini–Hochberg correction across the panel, and concordant MDD-minus-control direction across all available cohorts. NPTX2, EGR1, VGF, BDNF, and SAT1 met these criteria, with lower expression in MDD. The same five-gene pattern was supported by weighted signed Stouffer analysis, one-stage generalized least-squares models, random-effects meta-analysis, and 200,000 disease-label permutations; none produced at least five genes meeting the complete primary-support criterion (empirical p = 5.0 × 10−6). The most robust cross-cohort finding was a convergent lower-expression pattern across genes supporting redox-linked stress adaptation, polyamine homeostasis, neurotrophic signaling, activity-dependent transcription, and synaptic plasticity. This pattern suggests impaired molecular capacity for neuronal stress resilience and adaptive plasticity in MDD.