172. ALTERED PREFRONTAL CORTEX-BASED FUNCTIONAL CONNECTIVITY AND TRAIT IMPULSIVITY AMONG PATIENTS WITH BIPOLAR DISORDER AND HISTORY OF SUICIDE ATTEMPTS

Abstract Background Bipolar disorder (BD) accounts for the highest lifetime suicide attempt rates among psychiatric disorders, highlighting the need for effective suicide prevention strategies within this population. However, the neurobiological basis of impulsivity and its role in suicide attempt among patients with BD remains underexplored. Aims & Objectives This study aimed to examine the functional connectivity (FC) within the prefrontal cortex (PFC) in BD patients with and without a history of suicide attempt, focusing on the role of trait impulsivity. Method Seventy-two euthymic BD patients (34 with a history of suicide attempt, 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 after the adjustment of covariates and multiple testing correction by using the Benjamini–Hochberg false discovery method. Discussion & Conclusions Our previous study has found that trait impulsivity significantly correlated with structural changes over SFG, MFG, IFG, and OFC among BDSA by using structural MRI (MH Huang et al. J Affect Disord. 2023). The present study highlights specific PFC-based FC alterations associated with suicide attempts and trait impulsivity in BD, offering potential neurobiological markers for suicide risk in this population.