Background: The neurobiological basis of impulsivity and its role in suicide attempt (SA) in BD remains underexplored. This study aimed to examine the functional connectivity (FC) within the prefrontal cortex (PFC) in BD patients with and without a history of SA, focusing on the role of trait impulsivity.
Methods: Seventy-two euthymic BD patients (34 with a history of SA, BDSA; and 38 without, BDNS) and 55 age- and sex-matched healthy controls underwent resting-state functional MRI. FC analyses were conducted on four PFC regions: superior frontal gyrus (SFG), middle frontal gyrus (MFG), inferior frontal gyrus (IFG), and orbitofrontal cortex (OFC). Trait impulsivity was assessed using the Barratt Impulsiveness Scale (BIS-11), and its association with FC was analyzed using a general linear model, adjusting for demographic and clinical variables.
Results: BDSA had higher trait impulsivity than BDNS and the controls. BDSA exhibited reduced FC between the PFC and sensorimotor (postcentral and precentral gyri) and thalamic regions compared to BDNS. These reductions in FC of the fronto-thalamic and fronto-sensorimotor circuits were significantly associated with higher trait impulsivity scores.
Conclusion: The findings highlight specific PFC-based FC alterations associated with suicide attempts and trait impulsivity in BD, offering potential neurobiological markers for suicide risk in this population.
Keywords: impulsivity; prefrontal cortex; sensorimotor; suicide; thalamocortical.
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