Department of Psychiatry, University of Hong Kong, Queen Mary Hospital, 102 Pok Fu Lam Road, Pok Fu Lam, Hong Kong; State Key Laboratory of Brain and Cognitive Sciences, University of Hong Kong, Hong Kong.
Department of Psychiatry, University of Hong Kong, Queen Mary Hospital, 102 Pok Fu Lam Road, Pok Fu Lam, Hong Kong.
Eur Neuropsychopharmacol. 2019 May;29(5):629-642. doi: 10.1016/j.euroneuro.2019.03.006. Epub 2019 Mar 15.
Effort-based decision-making has recently been proposed as a potential mechanism contributing to motivational deficits (amotivation) in psychotic disorder. Previous research has identified altered effort allocation in chronic schizophrenia, but produced mixed results regarding its relationship with amotivation. No study has investigated effort allocation in first-episode psychosis (FEP). We examined effort-based decision-making in 45 clinically-stabilized FEP patients and 45 demographically-matched controls, using Effort-Expenditure for Reward Task (EEfRT) which measures allocation of physical effort for monetary reward at varying magnitude and probability levels. Our results showed that FEP patients did not demonstrate overall reduction in effort expenditure but displayed reduced willingness to expend effort for high-value/high-probability reward as compared to controls. In particular, such selective effort-related impairment was most pronounced in patients with high levels of amotivation. Furthermore, reduced allocation of greater effort for higher probability reward was related to poorer psychosocial functioning. Decreased effort exertion was generally unrelated to other symptom dimensions, self-report anhedonia, antipsychotic dose and cognitive deficits. This study thus provides the first evidence of effort-based decision-making impairment in FEP, and indicates that first-episode patients were not generally effort-averse but exhibited inefficient effort allocation by failing to make high-effort choices to maximize reward receipt. Our findings affirm the critical role of amotivation on aberrant effort allocation, and support the link between laboratory-based effort-cost measures and real-world psychosocial functioning in medicated FEP. Further longitudinal research is required to clarify trajectory of suboptimal effort allocation and its potential utility in predicting amotivation and functional outcomes in the early course of illness.
基于努力的决策最近被提出作为导致精神病障碍动机不足（动机缺乏）的潜在机制。先前的研究已经确定了慢性精神分裂症中努力分配的改变，但关于其与动机缺乏的关系产生了混合的结果。没有研究调查过首发精神病（FEP）中的努力分配。我们使用奖励努力支出任务（EEfRT）检查了 45 名临床稳定的 FEP 患者和 45 名匹配的对照者的基于努力的决策，该任务测量在不同大小和概率水平下为金钱奖励分配体力努力。我们的结果表明，FEP 患者并没有表现出整体努力支出减少，但与对照组相比，他们表现出对高价值/高概率奖励的意愿降低。特别是，这种选择性的与努力相关的损伤在动机缺乏水平较高的患者中最为明显。此外，为更高概率的奖励分配更多的努力与较差的社会心理功能有关。减少的努力投入通常与其他症状维度、自我报告的快感缺失、抗精神病药物剂量和认知缺陷无关。因此，这项研究首次提供了 FEP 中基于努力的决策受损的证据，并表明首发患者一般不是厌恶努力，而是通过未能做出最大程度地获得奖励的高努力选择来表现出低效的努力分配。我们的发现肯定了动机缺乏对异常努力分配的关键作用，并支持实验室基于努力成本的测量与药物治疗的 FEP 中的现实社会心理功能之间的联系。需要进一步的纵向研究来阐明次优努力分配的轨迹及其在预测疾病早期的动机缺乏和功能结果中的潜在效用。
