The Role of Temperament Traits in Bipolar Disorder: Neuroimaging Study

Purpose: This study aimed to identify temperament traits alterations in bipolar disorder (BD) and explore their potential neuroimaging correlates using resting-state functional magnetic resonance imaging. Methods: We assessed seed-to-voxel alterations in four large-scale brain networks (Salience, Frontoparietal, Default Mode, and SensoriMotor) in 49 patients with BD and 49 healthy individuals according to the difference of temperamental traits (Reward Dependence, Novelty Seeking, Harm Avoidance, and Persistence). Also, we measured the relationship of temperamental traits with the severity of manic and depressive symptoms and impulsivity. Results: Lower Reward Dependence (t-Welch's (87.1) = -2.50; p=0.014) in bipolar patients was associated with increased functional connectivity between Salience Network and Default Mode and FrontoParietal Networks. Higher Novelty Seeking (t-Welch's (87.3) = 4.37; p < 0.001) was associated with increased functional connectivity within FrontoParietal Network, whereas its functional connectivity with Visual and Dorsal Attention Networks was decreased. Higher Harm Avoidance (t-Welch's (82.8) = 4.85; p < 0.001) was associated with increased functional connectivity between FrontoParietal Network and basal ganglia. Lower Persistence (U = 998; p=0.002) was associated with decreased functional connectivity within FrontoParietal Network and with Default Mode Network. Higher persistence in bipolar patients was associated with greater severity of manic symptoms (Spearman's rho = 0.302, p=0.018), while lower Reward Dependence was associated with increased severity of depressive symptoms (Pearson's r = -0.388, p=0.003). Harm Avoidance negatively correlates with Persistence (Pearson's r = -0.525, p < 0.001) and positively with reward dependence (Pearson's r = -0.259, p=0.036). We also found a negative correlation between impulsivity and Reward Dependence (Pearson's r = -0.312, p=0.029) and positive correlation between impulsivity and Novelty Seeking (Pearson's r = 0.525, p < 0.001). Conclusions: The findings demonstrate a possible functional neuroimaging basis for altered temperamental traits in patients with bipolar disorder.