Objective

Disruptive mood dysregulation disorder (DMDD) codifies severe, chronic irritability. Youths with bipolar disorder (BD) also present with irritability, but with an episodic course. To date, it is not clear whether aberrant white matter microstructure—a well-replicated finding in BD—can be observed in DMDD and relates to symptoms of irritability.

Method

We acquired diffusion tensor imaging data from 118 participants (BD = 36, DMDD = 44, healthy volunteers (HV = 38). Images of fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) were processed with tract-based spatial statistics controlling for age and sex. The data were also used to train Gaussian process classifiers to predict diagnostic group.

Results

In BD vs DMDD, FA in the corticospinal tract was reduced. In DMDD vs HV, reductions in FA and AD were confined to the anterior corpus callosum. In BD vs HV, widespread reductions in FA and increased RD were observed. FA in the anterior corpus callosum and corticospinal tract was negatively associated with irritability. The Gaussian process classifier could not discriminate between BD and DMDD, but achieved 68% accuracy in predicting DMDD vs HV and 75% accuracy in predicting BD vs HV.

Conclusion

Aberrant white matter microstructure was associated with both categorical diagnosis and the dimension of irritability. Alterations in DMDD were regionally discrete and related to reduced AD. In BD, we observed widespread increases in RD, supporting the hypothesis of altered myelination in BD. These findings will contribute to the pathophysiological understanding of DMDD and its differentiation from BD.

Clinical trial registration information: Studies of Brain Function and Course of Illness in Pediatric Bipolar Disorder; https://clinicaltrials.gov/; NCT00025935; Child & Adolescent Bipolar Disorder Brain Imaging and Treatment Study; https://clinicaltrials.gov/; NCT00006177.

中文翻译：

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小儿双相情感障碍和破坏性情绪失调障碍中的白质微观结构。

客观的

破坏性情绪失调障碍 (DMDD) 是严重的慢性易怒症。患有双相情感障碍 (BD) 的青少年也表现出易怒，但有间歇性病程。迄今为止，尚不清楚是否可以在 DMDD 中观察到异常的白质微观结构（BD 中的一个很好复制的发现）并与易怒症状相关。

方法

我们从 118 名参与者（BD = 36，DMDD = 44，健康志愿者 (HV = 38)）那里获得了扩散张量成像数据。分数各向异性 (FA)、轴向扩散率 (AD) 和径向扩散率 (RD) 的图像是用道处理的-based spatial statistics controlling for age and sex. 这些数据还用于训练高斯过程分类器以预测诊断组。

结果

在 BD 与 DMDD 中，皮质脊髓束中的 FA 减少了。在 DMDD 与 HV 中，FA 和 AD 的减少仅限于前胼胝体。在 BD 与 HV 中，观察到 FA 广泛减少和 RD 增加。胼胝体前部和皮质脊髓束中的 FA 与易怒呈负相关。高斯过程分类器无法区分 BD 和 DMDD，但在预测 DMDD 与 HV 时达到 68% 的准确度，在预测 BD 与 HV 时达到 75% 的准确度。

结论

异常的白质微观结构与分类诊断和易怒程度相关。DMDD 的改变在区域上是离散的并且与减少的 AD 相关。在 BD 中，我们观察到 RD 普遍增加，支持 BD 中髓鞘形成改变的假设。这些发现将有助于对 DMDD 的病理生理学理解及其与 BD 的区别。

临床试验注册信息：小儿双相情感障碍的脑功能和病程研究；https://clinicaltrials.gov/；NCT00025935；儿童和青少年双相情感障碍脑成像和治疗研究；https://clinicaltrials.gov/；NCT00006177。