Tu P C, Kuan Y H, Li C T, Su T P
Department of Medical Research,Taipei Veterans General Hospital,Taipei 112,Taiwan.
Institute of Brain Science, National Yang-Ming University,Taipei,Taiwan.
Psychol Med. 2017 May;47(7):1292-1299. doi: 10.1017/S0033291716003299. Epub 2017 Jan 12.
Patients with bipolar disorder (BD) frequently exhibit impulsive behaviors independent of their mood state, and trait impulsivity is increasingly recognized as a crucial BD biomarker. This study aimed to investigate structural correlates of trait impulsivity measured using the Barratt Impulsiveness Scale (BIS) in healthy controls (HCs) and patients with BD.
We recruited 59 patients diagnosed with BD I or BD II (35.3 ± 8.5 years) and 56 age- and sex-matched HCs (33.9 ± 7.4 years). Participants underwent structural magnetic resonance imaging and clinical evaluations, and their BIS scores were evaluated. An automated surface-based method (FreeSurfer) was used to measure cortical thickness and generate thickness maps for each participant. Brain-wise regression analysis of the association between cortical thickness and BIS scores was performed separately for BD and HC groups by using a general linear model.
Patients with BD obtained significantly higher BIS scores than HCs. In HCs, higher BIS scores were associated with a thinner cortex in the left inferior, middle and medial frontal cortices. By contrast, in BD patients, higher BIS scores were associated with a thicker cortex in the right insula. Patients with BD showed a thinner cortex than HCs in all these four structures.
The findings indicate that the left prefrontal cortex plays a cardinal role in trait impulsivity of healthy individuals. Patients with BD have a different structural correlate of trait impulsivity in the right insula. However, the use of various psychotropics in patients with BD may limit our interpretation of BD findings.
双相情感障碍（BD）患者经常表现出与其情绪状态无关的冲动行为，且特质冲动性越来越被视为双相情感障碍的关键生物标志物。本研究旨在调查使用巴拉特冲动性量表（BIS）测量的特质冲动性在健康对照者（HCs）和双相情感障碍患者中的结构相关性。
我们招募了59名被诊断为双相I型或双相II型障碍的患者（35.3±8.5岁）和56名年龄及性别匹配的健康对照者（33.9±7.4岁）。参与者接受了结构磁共振成像和临床评估，并评估了他们的BIS分数。使用基于表面的自动方法（FreeSurfer）测量皮质厚度，并为每个参与者生成厚度图。通过使用一般线性模型，分别对双相情感障碍组和健康对照组进行皮质厚度与BIS分数之间关联的全脑回归分析。
双相情感障碍患者的BIS分数显著高于健康对照者。在健康对照者中，较高的BIS分数与左下额叶、中额叶和内侧额叶皮质较薄有关。相比之下，在双相情感障碍患者中，较高的BIS分数与右侧岛叶皮质较厚有关。在这四个结构中，双相情感障碍患者的皮质均比健康对照者薄。
研究结果表明，左侧前额叶皮质在健康个体的特质冲动性中起主要作用。双相情感障碍患者在右侧岛叶有不同的特质冲动性结构相关性。然而，双相情感障碍患者使用各种精神药物可能会限制我们对双相情感障碍研究结果的解释。
