From the MiNDS Neuroscience Graduate Program, McMaster University (Syan, Frey, Kapczinski, Hall, Minuzzi); the Women's Health Concerns Clinic (Syan, Frey, Remtulla, Minuzzi); the Mood Disorders Program, St. Joseph's Healthcare (Frey, Kapczinski, Minuzzi); the Department of Psychiatry and Behavioural Neurosciences, McMaster University (Smith, Frey, Kapczinski, Minuzzi, Smith); and the Department of Psychology, Neuroscience and Behaviour, McMaster University (Hall), Hamilton, Ontario, Canada.
J Psychiatry Neurosci. 2018 Aug;43(5):298-316. doi: 10.1503/jpn.170175.
Bipolar disorder is chronic and debilitating. Studies investigating resting-state functional connectivity in individuals with bipolar disorder may help to inform neurobiological models of illness.
We conducted a systematic review with the following goals: to summarize the literature on resting-state functional connectivity in bipolar disorder during clinical remission (euthymia) compared with healthy controls; to critically appraise the literature and research gaps; and to propose directions for future research. We searched PubMed/MEDLINE, Embase, PsycINFO, CINAHL and grey literature up to April 2017.
Twenty-three studies were included. The most consistent finding was the absence of differences in resting-state functional connectivity of the default mode network (DMN), frontoparietal network (FPN) and salience network (SN) between people with bipolar disorder and controls, using independent component analysis. However, 2 studies in people with bipolar disorder who were positive for psychosis history reported DMN hypoconnectivity. Studies using seed-based analysis largely reported aberrant resting-state functional connectivity with the amygdala, ventrolateral prefrontal cortex, cingulate cortex and medial prefrontal cortex in people with bipolar disorder compared with controls. Few studies used regional homogeneity or amplitude of low-frequency fluctuations.
We found heterogeneity in the analysis methods used.
Stability of the DMN, FPN and SN may reflect a state of remission. Further, DMN hypoconnectivity may reflect a positive history of psychosis in patients with bipolar disorder compared with controls, highlighting a potentially different neural phenotype of psychosis in people with bipolar disorder. Resting-state functional connectivity changes between the amygdala, prefrontal cortex and cingulate cortex may reflect a neural correlate of subthreshold symptoms experienced in bipolar disorder euthymia, the trait-based pathophysiology of bipolar disorder and/or a compensatory mechanism to maintain a state of euthymia.
双相情感障碍是一种慢性且使人虚弱的疾病。研究双相情感障碍患者的静息态功能连接有助于为疾病的神经生物学模型提供信息。
我们进行了一项系统评价，旨在总结静息态功能连接在双相情感障碍缓解期（即病情稳定）与健康对照组之间的研究文献；对文献进行批判性评估并找出研究空白；并为未来的研究提出方向。我们检索了 PubMed/MEDLINE、Embase、PsycINFO、CINAHL 和灰色文献，检索时间截至 2017 年 4 月。
共纳入 23 项研究。使用独立成分分析时，最一致的发现是双相情感障碍患者与对照组之间默认模式网络（DMN）、额顶网络（FPN）和突显网络（SN）的静息态功能连接没有差异。然而，2 项研究发现有精神病病史的双相情感障碍患者的 DMN 连接性降低。使用种子点分析法的研究大多报告双相情感障碍患者的静息态功能连接与杏仁核、腹外侧前额叶皮质、扣带回和内侧前额叶皮质异常，与对照组相比。少数研究使用局部一致性或低频波动幅度。
我们发现分析方法存在异质性。
DMN、FPN 和 SN 的稳定性可能反映了缓解状态。此外，与对照组相比，DMN 连接性降低可能反映了双相情感障碍患者有精神病阳性病史，这突出了双相情感障碍患者精神病的潜在不同神经表型。杏仁核、前额叶皮质和扣带回之间的静息态功能连接变化可能反映了双相情感障碍缓解期阈下症状的神经相关因素、双相情感障碍的特质性病理生理学，或是维持病情稳定的代偿机制。
