Structural brain abnormalities in patients with type I bipolar disorder and suicidal behavior

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Suicidal behavior is a significant concern in Bipolar Disorder Type I (BD-I).
• Previous research suggests frontolimbic network (FLN) abnormalities in BD-I patients who attempt suicide (SA).

Purpose of the Study:

• To investigate neuroanatomical differences in the FLN in BD-I patients with and without a history of SA.
• To identify potential neural signatures associated with suicidal behavior and its lethality in BD-I.

Main Methods:

• Voxel-based morphometry (VBM) was used to compare gray matter volume (GMV) between three groups: euthymic BD-I patients with SA (n=20), BD-I patients without SA (n=19), and healthy controls (HCs) (n=20).
• The medical lethality of previous SA was assessed.
• Statistical analysis included family-wise error (FWE) correction with small-volume correction.

Main Results:

• BD-I patients with SA showed significantly increased GMV in the right rostral anterior cingulate cortex (ACC) compared to those without SA.
• This ACC gray matter increase was more pronounced and extended to the left ACC in the high-lethality SA subgroup.
• GMV in the insula and orbitofrontal cortex correlated with the lethality of SA.

Conclusions:

• Morphological alterations in the FLN, specifically within the ACC, may serve as a neural signature for suicidal behavior in BD-I.
• These findings suggest that structural brain changes in the FLN are linked to the etiopathogenesis and severity of suicidality in BD-I patients.