The Treatment of Depression with Yoga and Walking

重度抑郁症（MDD）影响高达17%的人口，并且在高达40%的个体中没有得到有效治疗。有证据表明，负面情绪与副交感神经系统（PNS）活动减少有关，通过迷走神经张力测量。瑜伽练习和迷走神经刺激（VNS）都可以通过增加迷走神经张力来增加PNS活性。瑜伽疗法和迷走神经刺激都被证明可以改善抑郁症和癫痫的症状。使用磁共振波谱（MRS），脑γ-氨基丁酸（GABA）水平已被证明是低的MDD和癫痫的受试者，当相同的受试者与药物治疗，GABA水平增加，症状减轻。使用MRS，我们的研究小组已经表明，丘脑GABA水平在60分钟的瑜伽课程后上升，GABA水平的增加与情绪的改善有关。我们的假设是，PNS和GABA系统的低活性与抑郁症状有关，瑜伽干预将刺激PNS传入脑干核，从而观察到GABA水平的相关增加和抑郁症状的减少。在项目开始之前，将进行剂量和可行性研究。目的：一曰：测量并比较MDD和非抑郁健康受试者（ND）三个解剖结构（丘脑、海马和杏仁核复合体）的基线GABA水平。第二章：在MDD受试者中获得四次MRS扫描：基线（扫描1）; 12周瑜伽或步行干预后（扫描2）;扫描2后，受试者将立即完成60分钟的干预（瑜伽或步行）;随后进行扫描3，并在扫描2和3后两天再次进行（扫描4）。3：在研究过程中，使用心理仪器测量情绪变化，使用呼吸性窦性心律失常（RSA）测量PNS活动。假设：I：在所有ROI中，MDD组的基线GABA水平将低于ND组（即，丘脑、海马和海马/杏仁核复合体）。IIa和IIb：在分配到瑜伽组的MDD受试者中，紧张性GABA水平（扫描2-扫描1）将出现组内变化。当比较MDD瑜伽组和MDD步行组时，会有组间的紧张性GABA水平差异。IIIa和IIIb：MDD瑜伽组的急性GABA水平（扫描3-扫描2）将发生组内变化。当比较MDD瑜伽组和MDD步行组时，急性GABA水平会有组间差异。IV：GABA恢复水平无变化（扫描4 -扫描2）。五、六：GABA水平、情绪量表和扫描时获得的RSA将相互关联，因此GABA水平的增加与情绪改善、抑郁减轻和焦虑减轻有关。VII：与步行组相比，瑜伽组在干预过程中的情绪改善更大。

Major Depressive Disorder (MDD) affects up to 17% of the population and is not treated effectively in up to 40% of individuals. There is evidence that negative emotions are related to decreased activity in the parasympathetic nervous system (PNS) as measured by vagal tone. Both yoga practices and vagal nerve stimulation (VNS) can increase PNS activity by increasing vagal tone. Both yoga treatments and VNS have been shown to improve symptoms in depression and epilepsy. Using magnetic resonance spectroscopy (MRS), brain gamma-aminobutryic acid (GABA) levels have been shown to be low in subjects with MDD and epilepsy, and when the same subjects are treated with pharmacologic agents, GABA levels increase and symptoms decrease. Using MRS, our group has shown that thalamic GABA levels rise after a 60-minute yoga session and that increases in GABA levels are associated with improved mood. Our hypothesis is that low activity in the PNS and GABA systems is associated with depressive symptoms, and that a yoga intervention will stimulate the PNS afferents to brain stem nuclei, such that associated increases in GABA levels and decreased depressive symptoms will be observed. A dosing and feasibility study will be conducted prior to beginning the project. Aims: 1: To measure and compare baseline GABA levels in MDD and non-depressed healthy subjects (ND) in three anatomic structures, the thalamus, insula and hippocampal/amygdala complex. 2: To obtain four MRS scans in MDD subjects: Baseline (Scan 1); After 12- week yoga or walking interventions (Scan 2); Immediately after Scan 2, subjects will complete a 60-minute intervention (yoga or walking); Followed by Scan 3, and again two days after Scans 2 & 3 (Scan 4). 3: To measure changes in mood using psychological instruments and PNS activity using respiratory sinus arrhythmia (RSA) over the course of the study. Hypotheses: I: Baseline GABA levels will be lower in the MDD group compared to the ND group in all ROIs (i.e., thalamus, insula and hippocampal/amygdala complex). IIa & IIb: There will be a within-group change in tonic GABA levels (Scan 2-Scan 1) in the MDD subjects assigned to the yoga group. There will be a between-group difference in tonic GABA levels when comparing the MDD yoga group with the MDD walking group. IIIa & IIIb: There will be a within-group change in acute GABA levels (Scan 3-Scan 2) in the MDD yoga group. There will be a between-group difference in acute GABA levels when comparing the MDD yoga group with the MDD walking group. IV: There will be no change in recovery GABA levels (Scan 4 - Scan 2). V & VI: GABA levels, mood scales and RSA obtained at the time of scanning will be correlated, such that increasing GABA levels are associated with improved mood, decreased depression and decreased anxiety. VII: There will be a greater improvement in mood over the course of the interventions in the yoga group compared to the walking group.