Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, United States.
J Affect Disord. 2012 Feb;136(3):1126-34. doi: 10.1016/j.jad.2011.09.048. Epub 2011 Oct 28.
Although functional brain imaging has established that individuals with unipolar major depressive disorder (MDD) are characterized by frontostriatal dysfunction during reward processing, no research to date has examined the chronometry of neural responses to rewards in euthymic individuals with a history of MDD.
A monetary incentive delay task was used during fMRI scanning to assess neural responses in frontostriatal reward regions during reward anticipation and outcomes in 19 participants with remitted major depressive disorder (rMDD) and in 19 matched control participants.
During the anticipation phase of the task, the rMDD group was characterized by relatively greater activation in bilateral anterior cingulate gyrus, in right midfrontal gyrus, and in the right cerebellum. During the outcome phase of the task, the rMDD group was characterized by relatively decreased activation in bilateral orbital frontal cortex, right frontal pole, left insular cortex, and left thalamus. Exploratory analyses indicated that activation within a right frontal pole cluster that differentiated groups during reward anticipation predicted the number of lifetime depressive episodes within the rMDD group.
Replication with larger samples is needed.
Results suggest a double dissociation between reward network reactivity and temporal phase of the reward response in rMDD, such that rMDD is generally characterized by reward network hyperactivation during reward anticipation and reward network hypoactivation during reward outcomes. More broadly, these data suggest that aberrant frontostriatal response to rewards may potentially represent a trait marker for MDD, though future research is needed to evaluate the prospective utility of this functional neural endophenotype as a marker of MDD risk.
尽管功能性脑成像已经证实，单相重性抑郁障碍（MDD）患者在奖励处理过程中表现出额-纹状体功能障碍，但迄今为止，尚无研究探讨既往 MDD 病史的缓解期个体对奖励的神经反应的时间进程。
在 fMRI 扫描期间使用货币奖励延迟任务，以评估 19 名缓解期重性抑郁障碍（rMDD）患者和 19 名匹配对照参与者在奖励预期和结果期间额-纹状体奖励区域的神经反应。
在任务的预期阶段，rMDD 组双侧前扣带回、右侧额中回和右侧小脑的激活相对较大。在任务的结果阶段，rMDD 组双侧眶额皮质、右侧额极、左侧岛叶和左侧丘脑的激活相对减少。探索性分析表明，在区分奖励预期阶段组别的右额极簇内的激活，可预测 rMDD 组内的终生抑郁发作次数。
需要更大样本的复制。
结果表明，rMDD 中奖励网络反应性和奖励反应的时间阶段之间存在双重分离，即 rMDD 通常在奖励预期期间表现出奖励网络过度激活，而在奖励结果期间表现出奖励网络激活不足。更广泛地说，这些数据表明，对奖励的异常额-纹状体反应可能潜在地代表 MDD 的特征标记，尽管需要进一步研究来评估这种功能神经内表型作为 MDD 风险标志物的前瞻性效用。
