Neuromarkers in bipolar disorder: A narrative review bridging neuroscience and clinical practice

Bipolar disorder is a chronic, disabling psychiatric condition characterized by recurrent mood episodes and substantial functional impairment. Its diagnosis and management remain largely reliant on clinical observation, with limited objective tools to support early detection, differential diagnosis, or treatment planning. In recent years, neuromarkers, which are biological indicators reflecting neural structure, function, genetics, and inflammation, have emerged as promising candidates to bridge this gap. This narrative review aims to explore the clinical relevance of neuromarkers in bipolar disorder, including findings from neuroimaging, electrophysiology, genetics, and immunology. Structural and functional neuroimaging consistently points to dysregulation in fronto-limbic circuits involved in emotional regulation, while electroencephalo-graph-based markers reveal abnormal patterns of cortical excitability and connectivity. Genetic studies have identified susceptibility loci and polygenic risk scores that may help stratify patients based on risk or treatment response. Concurrently, inflammatory markers such as cytokines and C-reactive protein have been associated with mood states, disease progression, and treatment resistance. Although none of these markers are currently used in routine clinical practice, accumulating evidence suggests that integrating neuromarkers into clinical assessment could improve diagnostic accuracy, predict mood episode recurrence, and guide individualized treatment approaches in patients with bipolar disorder. This review highlights key findings, discusses challenges in clinical translation, such as variability, reproducibility, and cost-effectiveness, and proposes future directions to move the field toward clinically actionable applications of neuromarkers in bipolar disorder.