Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts; Black Dog Institute, University of New South Wales, Randwick, New South Wales, Australia.
Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2021 Jul;6(7):706-715. doi: 10.1016/j.bpsc.2021.01.004. Epub 2021 Jan 26.
The National Institute of Mental Health Research Domain Criteria (RDoC) initiative aims to establish a neurobiologically valid framework for classifying mental illness. Here, we examined whether the RDoC construct of reward learning and three aspects of its underlying neurocircuitry predicted symptom trajectories in individuals with mood pathology.
Aligning with the RDoC approach, we recruited individuals (n = 80 with mood disorders [58 unipolar and 22 bipolar] and n = 32 control subjects; 63.4% female) based on their performance on a laboratory-based reward learning task rather than clinical diagnosis. We then assessed 1) anterior cingulate cortex prediction errors using electroencephalography, 2) striatal reward prediction errors using functional magnetic resonance imaging, and 3) medial prefrontal cortex glutamatergic function (mPFC Gln/Glu) using H magnetic resonance spectroscopy. Severity of anhedonia, (hypo)mania, and impulsivity were measured at baseline, 3 months, and 6 months.
Greater homogeneity in aspects of brain function (mPFC Gln/Glu) was observed when individuals were classified according to reward learning ability rather than diagnosis. Furthermore, mPFC Gln/Glu levels predicted more severe (hypo)manic symptoms cross-sectionally, predicted worsening (hypo)manic symptoms longitudinally, and explained greater variance in future (hypo)manic symptoms than diagnostic information. However, rather than being transdiagnostic, this effect was specific to individuals with bipolar disorder. Prediction error indices were unrelated to symptom severity.
Although findings are preliminary and require replication, they suggest that heightened mPFC Gln/Glu warrants further consideration as a predictor of future (hypo)mania. Importantly, this work highlights the value of an RDoC approach that works in tandem with, rather than independent of, traditional diagnostic frameworks.
美国国立精神卫生研究所的研究领域标准（RDoC）计划旨在建立一个具有神经生物学效度的精神疾病分类框架。在这里，我们研究了 RDoC 的奖励学习结构及其潜在神经回路的三个方面是否可以预测具有心境病理的个体的症状轨迹。
我们根据个体在实验室奖励学习任务中的表现（而非临床诊断）招募了 80 名（58 名单相和 22 名双相心境障碍患者和 32 名对照受试者；女性占 63.4%）参与者，以此来与 RDoC 方法保持一致。然后，我们评估了 1）使用脑电图记录的前扣带回皮层预测错误，2）使用功能磁共振成像记录的纹状体奖励预测错误，3）使用 H 磁共振波谱记录的内侧前额叶皮层谷氨酸能功能（mPFC Gln/Glu）。在基线、3 个月和 6 个月时，我们测量了快感缺失、（轻）躁狂和冲动的严重程度。
当根据奖励学习能力而不是诊断对个体进行分类时，观察到大脑功能（mPFC Gln/Glu）的各个方面更加一致。此外，mPFC Gln/Glu 水平可以预测更严重的（轻）躁狂症状的横断面，预测（轻）躁狂症状的恶化，比诊断信息能更好地解释未来（轻）躁狂症状的变异性。但是，这种影响不是跨诊断的，而是针对双相障碍患者的。预测误差指数与症状严重程度无关。
尽管研究结果尚属初步且需要重复，但它们表明，mPFC Gln/Glu 水平升高值得进一步研究作为未来（轻）躁狂的预测因子。重要的是，这项工作强调了 RDoC 方法的价值，该方法与传统的诊断框架相辅相成，而不是独立于其之外。
