Department of Psychiatry, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing 210029, China.
Nanjing Brain Hospital, Medical School of Nanjing University, Nanjing 210093, China.
Neuroimage Clin. 2023;38:103433. doi: 10.1016/j.nicl.2023.103433. Epub 2023 May 16.
The psychomotor disturbance is a common symptom in patients with major depressive disorder (MDD). The neurological mechanisms of psychomotor disturbance are intricate, involving alterations in the structure and function of motor-related regions. However, the relationship among changes in the spontaneous activity, motor-related activity, local cortical thickness, and psychomotor function remains unclear.
A total of 140 patients with MDD and 68 healthy controls performed a simple right-hand visuomotor task during magnetoencephalography (MEG) scanning. All patients were divided into two groups according to the presence of psychomotor slowing. Spontaneous beta power, movement-related beta desynchronization (MRBD), absolute beta power during movement and cortical characteristics in the bilateral primary motor cortex were compared using general linear models with the group as a fixed effect and age as a covariate. Finally, the moderated mediation model was tested to examine the relationship between brain metrics with group differences and psychomotor performance.
The patients with psychomotor slowing showed higher spontaneous beta power, movement-related beta desynchronization and absolute beta power during movement than patients without psychomotor slowing. Compared with the other two groups, significant decreases were found in cortical thickness of the left primary motor cortex in patients with psychomotor slowing. Our moderated mediation model showed that the increased spontaneous beta power indirectly affected impaired psychomotor performance by abnormal MRBD, and the indirect effects were moderated by cortical thickness.
These results suggest that patients with MDD have aberrant cortical beta activity at rest and during movement, combined with abnormal cortical thickness, contributing to the psychomotor disturbance observed in this patient population.
精神运动障碍是重度抑郁症（MDD）患者的常见症状。精神运动障碍的神经机制复杂，涉及运动相关区域的结构和功能改变。然而，自发性活动、运动相关活动、局部皮质厚度和精神运动功能之间的变化关系尚不清楚。
共有 140 名 MDD 患者和 68 名健康对照者在脑磁图（MEG）扫描期间进行了简单的右手视觉运动任务。所有患者根据是否存在精神运动迟缓分为两组。使用一般线性模型，以组为固定效应，年龄为协变量，比较自发β功率、运动相关β去同步（MRBD）、运动期间的绝对β功率以及双侧初级运动皮质的皮质特征。最后，测试了调节中介模型，以检验大脑指标与组间差异和精神运动表现之间的关系。
精神运动迟缓的患者表现出比没有精神运动迟缓的患者更高的自发性β功率、运动相关β去同步和运动期间的绝对β功率。与其他两组相比，精神运动迟缓患者的左侧初级运动皮质皮质厚度明显降低。我们的调节中介模型表明，自发β功率的增加通过异常的 MRBD 间接影响受损的精神运动表现，而间接效应受皮质厚度的调节。
这些结果表明，MDD 患者在休息和运动期间皮质β活动异常，伴有皮质厚度异常，导致该患者群体观察到的精神运动障碍。
