Department of Psychology, Harvard University.
Department of Psychology, University of Rochester.
J Abnorm Psychol. 2019 Jan;128(1):44-56. doi: 10.1037/abn0000389. Epub 2018 Nov 29.
Reward dysfunction is often present in youth with major depressive disorder (MDD), but the specific neurobiological bases underlying reward valuation deficits remain unclear. The current study examined whether adolescents and young adults with MDD track brain and behavioral responses according to relative reward magnitude-a neurocognitive valuation process known as magnitude tracking. Female adolescents and young adults ages 15-20 years (n = 56 with current or past-year MDD; n = 26 healthy controls [HCs]) completed a task during functional neuroimaging in which they could win or lose money at high stakes (+$1/-50¢) and low stakes (+20¢/-10¢). Behaviorally, HC accelerated button press responses on high stakes compared to low-stakes trials, whereas MDD did not alter response speed across stakes. Neurally, HC increased recruitment of the ventral and dorsal striatum, canonical reward-processing regions, for high-magnitude versus low-magnitude rewards. However, the MDD group did not exhibit striatal magnitude tracking for low versus high rewards-an effect independent of MDD recency, MDD symptom severity, comorbid anxiety and substance use disorders, and psychiatric medication use. In contrast, striatal recruitment for overall reward reactivity, measured by comparing striatal activity for reward and loss feedback, was similar in the MDD and HC groups. However, reward reactivity was negatively correlated with current depression symptom severity in the MDD group. Taken together, these findings suggest that whereas reward reactivity may vary with current depression severity, reward magnitude tracking may represent an important aberrant valuation process in youth with depression-independent of symptom severity and recency. This valuation deficit may have implications for maladaptive motivation and learning observed in youth with MDD. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
奖励功能障碍在患有重度抑郁症（MDD）的年轻人中经常出现，但支持奖励估值缺陷的具体神经生物学基础仍不清楚。本研究考察了患有 MDD 的青少年和年轻人是否根据相对奖励大小跟踪大脑和行为反应 - 一种称为幅度跟踪的神经认知估值过程。15-20 岁的女性青少年和年轻人（当前或过去一年患有 MDD 的 n = 56；健康对照组 [HC] n = 26）在功能神经影像学期间完成了一项任务，他们可以在高赌注（+$1/-50¢）和低赌注（+20¢/-10¢）中赢得或输掉钱。行为上，HC 与低赌注相比，加快了高赌注试验的按钮按压反应，而 MDD 没有改变赌注之间的反应速度。神经上，HC 增加了腹侧和背侧纹状体的募集，这是经典的奖励处理区域，用于高幅度与低幅度奖励。然而，MDD 组在低幅度与高幅度奖励之间没有表现出纹状体幅度跟踪 - 这种效应独立于 MDD 的近期性、MDD 症状严重程度、共患焦虑和物质使用障碍以及精神科药物使用。相比之下，MDD 和 HC 组的总体奖励反应性的纹状体募集相似，通过比较奖励和损失反馈的纹状体活动来衡量。然而，在 MDD 组中，奖励反应性与当前抑郁症状严重程度呈负相关。总的来说，这些发现表明，尽管奖励反应性可能因当前抑郁严重程度而异，但奖励幅度跟踪可能代表抑郁青少年中一种重要的异常估值过程，与症状严重程度和近期性无关。这种估值缺陷可能对患有 MDD 的年轻人中观察到的适应不良动机和学习产生影响。（PsycINFO 数据库记录（c）2019 APA，保留所有权利）。
