Abstract / Summary
Background Bipolar disorder (BD) shows heterogeneous, mood-state–dependent network changes, complicating the identification of stable biomarkers and treatment targets.Objective This review proposes a Hemispheric Framework to organize findings on hemispheric alterations in BD and guide their investigation and therapeutic interpretation.Main Content The framework comprises three axes: Allocation, Integration, and Constraint. Allocation describes how processing load is distributed across hemispheres at baseline and reconfigured by mood state or task demands. Integration captures the effectiveness of cross-hemisphere coordination; electrophysiological and resting-state studies frequently indicate weaker synchrony and reduced interhemispheric coupling in BD. Constraint refers to biological limits on hemispheric reconfiguration, including callosal pathways, myelin and oligodendrocyte support, and neurotransmitter-system gradients. Together, these axes distinguish altered hemispheric recruitment from effective interhemispheric coordination and provide predefined readouts for longitudinal and perturb-and-measure studies.Conclusions The framework offers a reporting layer for neuromodulation studies by enabling Allocation and Integration to be assessed alongside symptoms before and after stimulation. Divergence between clinical and hemispheric changes may clarify treatment mechanisms, dose–response relationships, durability, and constraint-limited responses.