Motivation, Brain & Behavior lab Institut du Cerveau, Hôpital Pitié-Salpêtrière, Paris, France; Université Paris Cité, Paris, France; Department of Psychiatry, Service Hospitalo-Universitaire, GHU Paris Psychiatrie & Neurosciences, Paris, France.
Motivation, Brain & Behavior lab Institut du Cerveau, Hôpital Pitié-Salpêtrière, Paris, France; Université Paris Cité, Paris, France; Department of Psychiatry, Service Hospitalo-Universitaire, GHU Paris Psychiatrie & Neurosciences, Paris, France.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2022 Nov;7(11):1158-1169. doi: 10.1016/j.bpsc.2022.07.011. Epub 2022 Aug 8.
Motivational deficit is a core clinical manifestation of depression and a strong predictor of treatment failure. However, the underlying mechanisms, which cannot be accessed through conventional questionnaire-based scoring, remain largely unknown. According to decision theory, apathy could result either from biased subjective estimates (of action costs or outcomes) or from dysfunctional processes (in making decisions or allocating resources).
Here, we combined a series of behavioral tasks with computational modeling to elucidate the motivational deficits of 35 patients with unipolar or bipolar depression under various treatments compared with 35 matched healthy control subjects.
The most striking feature, which was observed independent of medication across preference tasks (likeability ratings and binary decisions), performance tasks (physical and mental effort exertion), and instrumental learning tasks (updating choices to maximize outcomes), was an elevated sensitivity to effort cost. By contrast, sensitivity to action outcomes (reward and punishment) and task-specific processes were relatively spared.
These results highlight effort cost as a critical dimension that might explain multiple behavioral changes in patients with depression. More generally, they validate a test battery for computational phenotyping of motivational states, which could orientate toward specific medication or rehabilitation therapy, and thereby help pave the way for more personalized medicine in psychiatry.
动机不足是抑郁症的核心临床症状，也是治疗失败的强有力预测指标。然而，无法通过传统的基于问卷的评分来获得潜在机制，这在很大程度上仍是未知的。根据决策理论，冷漠可能是由于主观估计（对行动成本或结果的偏见）或决策过程（或资源分配）出现功能障碍导致的。
在这里，我们结合了一系列行为任务和计算模型，以阐明 35 名单相或双相抑郁症患者在各种治疗下的动机不足，与 35 名匹配的健康对照受试者进行比较。
最引人注目的特征是，无论在偏好任务（喜欢程度评分和二进制决策）、绩效任务（体力和脑力付出）和工具性学习任务（更新选择以最大化结果）中，都观察到独立于药物的努力成本敏感性升高。相比之下，对行动结果（奖励和惩罚）和任务特定过程的敏感性相对保留。
这些结果强调了努力成本作为一个关键维度，可能解释了抑郁症患者的多种行为变化。更普遍地说，它们验证了用于计算动机状态表型的测试组合，这可以针对特定的药物治疗或康复治疗进行定向，从而为精神病学中的更个性化的医学铺平道路。
