Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029-6574, USA.
J Am Acad Child Adolesc Psychiatry. 2013 Jun;52(6):628-41.e13. doi: 10.1016/j.jaac.2013.04.003. Epub 2013 May 3.
Striatum-based circuits have been implicated in both major depressive disorder (MDD) and anhedonia, a symptom that reflects deficits of reward processing. Yet adolescents with MDD often exhibit a wide range of anhedonia severity. Addressing this clinical phenomenon, we aimed to use intrinsic functional connectivity (iFC) to study striatum-based circuitry in relation to categorical diagnosis of MDD and anhedonia severity.
A total of 21 psychotropic medication-free adolescents with MDD and 21 healthy controls (HC), group-matched for age and sex, underwent resting-state functional magnetic resonance imagining (fMRI) scans. Voxelwise maps indicating correlation strengths of spontaneous blood-oxygenation-level-dependent (BOLD) signals among 6 bilateral striatal seeds (dorsal caudate, ventral caudate, nucleus accumbens, dorsal-rostral putamen, dorsal-caudal putamen, ventral-rostral putamen) and the remaining brain regions were compared between groups. Relationships between striatal iFC and severity of MDD and anhedonia were examined in the MDD group. Analyses were corrected for multiple comparisons.
Adolescents with MDD manifested increased iFC between all striatal regions bilaterally and the dorsomedial prefrontal cortex (dmPFC), as well as between the right ventral caudate and the anterior cingulate cortex (ACC). MDD severity was associated with iFC between the striatum and midline structures including the precuneus, posterior cingulate cortex, and dmPFC. However, distinct striatal iFC patterns involving the pregenual ACC, subgenual ACC, supplementary motor area, and supramarginal gyrus were associated with anhedonia severity.
Although MDD diagnosis and severity were related to striatal networks involving midline cortical structures, distinct circuits within the reward system were associated with anhedonia. Findings support the incorporation of both categorical and dimensional approaches in neuropsychiatric research.
纹状体为基础的回路既与重度抑郁症（MDD）有关，也与快感缺失有关，快感缺失反映了奖赏加工的缺陷。然而，患有 MDD 的青少年通常表现出广泛的快感缺失严重程度。为了解决这一临床现象，我们旨在使用内在功能连接（iFC）研究与 MDD 的分类诊断和快感缺失严重程度相关的纹状体为基础的电路。
共有 21 名未服用精神药物的 MDD 青少年和 21 名健康对照者（HC），按年龄和性别进行分组匹配，接受静息状态功能磁共振成像（fMRI）扫描。比较组间 6 个双侧纹状体种子（背侧尾状核、腹侧尾状核、伏隔核、背侧-前侧壳核、背侧-后侧壳核、腹侧-前侧壳核）和其余脑区之间自发血氧水平依赖（BOLD）信号相关强度的体素图。在 MDD 组中，检查了纹状体 iFC 与 MDD 和快感缺失严重程度的关系。分析校正了多重比较。
MDD 青少年双侧所有纹状体区域与背内侧前额叶皮质（dmPFC）之间以及右侧腹侧尾状核与前扣带皮质（ACC）之间的 iFC 增加。MDD 严重程度与纹状体与包括楔前叶、后扣带皮质和 dmPFC 在内的中线结构之间的 iFC 相关。然而，涉及前扣带皮质、扣带回下皮质、辅助运动区和缘上回的不同纹状体 iFC 模式与快感缺失严重程度相关。
尽管 MDD 诊断和严重程度与涉及中线皮质结构的纹状体网络有关，但奖励系统内的不同回路与快感缺失有关。研究结果支持在神经精神研究中同时采用分类和维度方法。
