| Bipolar Disorder (BD) is a complex mental illness characterized by mood fluctuations, excitability, and impaired functioning. Anxiety in BD patients frequently leads to increased clinical symptoms, worse social functioning, and a higher risk of suicide, making it more difficult to treat. Current research on BD with anxiety symptoms (with anxiety distress or comorbid anxiety disorder) primarily examined clinical characteristics, prevalence, and treatment, with limited focus on its neuro-biogenetic mechanisms. The findings in this area were also inconsistent. Magnetic Resonance Imaging (MRI), known for its non-invasive nature and high resolution, is extensively utilized in investigating disease mechanisms. This technology aids in examining brain structure and function, enhancing our comprehension of the neurobiological underpinnings of various diseases and informing clinical treatment strategies. Consequently, this paper aimed to comprehensively review progress in brain MRI studies on BD patients with anxiety symptoms, aiming to discern stable changes in brain structure and function, thereby enriching our understanding of the neurobiological etiology of this condition. Additionally, this review seeks to offer valuable insights for clinical pharmacological research, diagnosis, and treatment strategies. Covering 14 original studies, it synthesized findings on brain structure and function, consistently highlighting functional activity changes in the frontal lobe, posterior cingulate cortex, temporal lobe, and angular gyrus, and structural changes predominantly in the left hippocampus and medial frontal gyrus. However, the consistency of results could be enhanced. Given the limited number of research in this field, bigger and more homogenous clinical populations, as well as longitudinal designs, are expected to be used for verification and supplementation. |