Rai Sabina, Griffiths Kristi R, Breukelaar Isabella A, Barreiros Ana R, Boyce Philip, Hazell Philip, Foster Sheryl L, Malhi Gin S, Harris Anthony W F, Korgaonkar Mayuresh S
Brain Dynamics Centre, Westmead Institute for Medical Research, The University of Sydney, Westmead, Sydney, New South Wales, Australia.
Faculty of Medicine and Health, Westmead Clinical School, The University of Sydney, Sydney, New South Wales, Australia.
Bipolar Disord. 2022 Dec;24(8):795-805. doi: 10.1111/bdi.13248. Epub 2022 Aug 25.
Despite homogenous clinical presentations between bipolar and unipolar disorders, there are distinct neurobiological differences. Chronicity of illness may be a factor impacting and sustaining certain neural features. The goal of this study was to investigate common and shared neural mechanisms underlying mood disorders, and possible sustained neural changes relating to illness chronicity by investigating a cohort of euthymic patients with bipolar disorder (BD), unipolar depression who had responded to treatment (treatment-sensitive depression, TSD), and a chronically treatment-resistant depressed (TRD) group.
One hundred and seventy-two participants (40 BD, 39 TSD, 40 TRD, and 53 age-gender-matched healthy controls) underwent resting-state fMRI scans. Seed-based and independent component analyses were performed to investigate group differences in resting-state connectivity between the four groups.
All three clinical groups had significantly lower connectivity within the frontoparietal network (FPN) relative to controls. TRD and BD were significantly different from TSD (TRD, BD > TSD) but were not significantly different from each other. TRDs were also significantly different from both BD and TSD for salience network connectivity with the posterior cingulate (DMN) and the FPN with frontal pole (DMN). Additionally, the BD group exhibited greater DMN-FPN (sgACC-RDLPFC) connectivity relative to TRD, TSD, and controls, which was correlated with a previous number of depressive episodes, in the BD group only.
BD demonstrated shared and differential connectivity features relative to symptomatic TRD and euthymic TSD groups. The increased sgACC-RDLPFC connectivity in BD and its correlation with a number of depressive episodes could be a neural feature associated with illness chronicity.
尽管双相情感障碍和单相情感障碍在临床表现上具有同质性，但它们在神经生物学上存在明显差异。疾病的慢性病程可能是影响和维持某些神经特征的一个因素。本研究的目的是通过调查一组双相情感障碍（BD）的心境正常患者、对治疗有反应的单相抑郁症患者（治疗敏感型抑郁症，TSD）以及慢性治疗抵抗性抑郁症（TRD）患者，来探究心境障碍潜在的共同神经机制，以及与疾病慢性病程相关的可能持续存在的神经变化。
172名参与者（40名BD患者、39名TSD患者、40名TRD患者和53名年龄与性别匹配的健康对照者）接受了静息态功能磁共振成像扫描。采用基于种子点的分析和独立成分分析来研究四组之间静息态连接性的组间差异。
与对照组相比，所有三个临床组在前额叶顶叶网络（FPN）内的连接性均显著降低。TRD组和BD组与TSD组存在显著差异（TRD、BD > TSD），但彼此之间无显著差异。TRD组在突显网络与后扣带回（默认模式网络，DMN）以及FPN与额极（DMN）的连接性方面，也与BD组和TSD组存在显著差异。此外，仅在BD组中，BD组相对于TRD组、TSD组和对照组表现出更强的DMN - FPN（前扣带回膝下部分 - 右侧背外侧前额叶皮质）连接性，这与之前的抑郁发作次数相关。
与有症状的TRD组和心境正常的TSD组相比，BD表现出共同和不同的连接性特征。BD组中前扣带回膝下部分 - 右侧背外侧前额叶皮质连接性增加及其与抑郁发作次数的相关性，可能是与疾病慢性病程相关的一种神经特征。
