Ventricular volume, white matter alterations and outcome of major depression and their relationship to endocrine parameters – A pilot study

<b>Objectives:</b> Brain morphology and its relation to endocrine parameters were examined, in order to determine the link of these parameters to treatment outcome to psychopharmacological treatment in depressed patients. <b>Methods:</b> We examined the potentially predictive value of Magnetic Resonance Imaging (MRI) parameters related to mineralocorticoid receptor (MR) function on the treatment outcome of depression. 16 inpatients with a major depressive episode (MDE) were studied at baseline and 14 of them approximately six weeks later. Physiological biomarkers and 3-T-structural MRI based volume measures, using FreeSurfer 6.0 software, were determined. <b>Results:</b> Non-responders (&lt;50% reduction of HAMD-21; <i>n</i> = 6) had a significantly smaller volume of the right anterior cingulate cortex, a significantly larger ventricle to brain ratio (VBR) and third ventricle volume, and smaller volumes of the central and central-anterior corpus callosum (CC) in comparison to responders (<i>n</i> = 7; all <i>p</i> ≤ 0.05). Correlational analysis (Spearman) demonstrated that larger ventricle volume was correlated to a worse treatment outcome, higher body mass index (BMI) and smaller CC segment volume, whereas the total CC volume was negatively correlated to the saliva aldosterone/cortisol concentration ratio (AC-ratio). <b>Conclusion:</b> Large ventricular volume may be a predictive marker for worse treatment response to standard antidepressant treatment, potentially via compression of white matter structures. A mediating role of the previously identified markers BMI and the AC-ratio, is suggested.<b>研究目标:</b> 本研究旨在探讨大脑形态及其与内分泌参数的关联，以明确上述参数与抑郁症患者接受精神药物治疗后的治疗结局之间的联系。<b>研究方法:</b> 本研究探讨与盐皮质激素受体（mineralocorticoid receptor, MR）功能相关的磁共振成像（Magnetic Resonance Imaging, MRI）参数对抑郁症治疗结局的潜在预测价值。共纳入16名重度抑郁发作（major depressive episode, MDE）住院患者，于基线阶段开展评估，其中14名患者在约6周后完成随访。研究采集了生理生物标志物数据，并使用FreeSurfer 6.0软件获取基于3T结构MRI的体积测量值。<b>研究结果:</b> 与应答者（n=7；所有p值均≤0.05）相比，无应答者（汉密尔顿抑郁量表21项版[HAMD-21]减分率<50%；n=6）的右侧前扣带回皮层体积显著更小，脑室-脑体积比（ventricle to brain ratio, VBR）及第三脑室体积显著更大，中央及中央前部胼胝体（corpus callosum, CC）体积更小。相关性分析（斯皮尔曼[Spearman]相关）结果显示，更大的脑室体积与更差的治疗结局、更高的体重指数（body mass index, BMI）及更小的胼胝体节段体积呈正相关；而总胼胝体体积与唾液醛固酮/皮质醇浓度比（aldosterone/cortisol concentration ratio, AC-ratio）呈负相关。<b>研究结论:</b> 较大的脑室体积可能是标准抗抑郁治疗应答不佳的预测标志物，其潜在机制可能与白质结构受压有关。本研究提示此前已明确的标志物BMI及AC-ratio可能发挥中介作用。