Department of Psychosomatic Medicine and Psychotherapy, TU Dresden, Dresden, Germany.
Department of Psychosomatic Medicine and Psychotherapy, TU Dresden, Dresden, Germany.
J Affect Disord. 2018 Mar 15;229:193-198. doi: 10.1016/j.jad.2017.12.047. Epub 2017 Dec 28.
Major Depression is mainly related to structural and functional alterations in brain networks involving limbic and prefrontal regions. Reduced olfactory sensitivity in depression is associated with reduced olfactory bulb (OB) volume. We determined if the OB volume reduction is a specific biomarker for depression and whether its diagnostic accuracy allows its use as a valid biomarker to support its diagnosis.
84 in-patients with mixed mental disorders and 51 age-matched healthy controls underwent structural MR imaging with a spin-echo T2-wheighted sequence. Individual OB volume was calculated manually (interrater-reliability = .81, p < .001) and compared between groups. Multiple regression analysis with OB volume as dependent variable and Receiver Operator Characteristic analysis to obtain its diagnostic accuracy for depression were ruled out.
Patients exhibited a 13.5% reduced OB volume. Multiple regression analysis showed that the OB volume variation was best explained by depression (β = -.19), sex (β = -.31) and age (β = -.29), but not by any other mental disorder. OB volume attained a diagnostic accuracy of 68.1% for depression.
The patient group mainly contained highly comorbid patients with mostly internalizing disorders which limits the generalisability of the results of the regression analysis.
The OB may serve as a marker for depression. We assume that reduced neural olfactory input to subsequent limbic and salience processing structures moderates this relation. However, the OB was in an inferior position compared to conventional questionnaires for diagnosis of depression. Combination with further structural or functional measurements is suggested.
重度抑郁症主要与涉及边缘和前额区域的脑网络的结构和功能改变有关。抑郁症嗅觉敏感性降低与嗅球（OB）体积减小有关。我们确定 OB 体积减小是否是抑郁症的特异性生物标志物，以及其诊断准确性是否允许将其用作有效的生物标志物来支持其诊断。
84 名混合性精神障碍住院患者和 51 名年龄匹配的健康对照者接受了自旋回波 T2 加权序列的结构磁共振成像。手动计算个体 OB 体积（组内可靠性 =.81，p <.001），并在组间进行比较。排除了以 OB 体积为因变量的多元回归分析和获得其对抑郁症诊断准确性的接收器操作特征分析。
患者的 OB 体积减少了 13.5%。多元回归分析显示，OB 体积的变化主要由抑郁症（β = -.19）、性别（β = -.31）和年龄（β = -.29）解释，但不受任何其他精神障碍的影响。OB 体积对抑郁症的诊断准确性为 68.1%。
患者组主要包含高度共病患者，且大多数为内化障碍，这限制了回归分析结果的普遍性。
OB 可能是抑郁症的标志物。我们假设，向随后的边缘和突显处理结构的减少的神经嗅觉输入调节了这种关系。然而，与传统的抑郁症诊断问卷相比，OB 的地位较低。建议与进一步的结构或功能测量相结合。
