Schizophrenia (SZ) is typically preceded by a prodromal (i.e. pre-illness) period characterized by attenuated positive symptoms and declining functional outcome. Negative symptoms are prominent among individuals at clinical high-risk (CHR) for psychosis (i.e. those with prodromal syndromes) and predictive of conversion to illness. Mechanisms underlying negative symptoms are unclear in the CHR population.

The current study evaluated whether CHR participants demonstrated deficits in the willingness to expend effort for rewards and whether these impairments are associated with negative symptoms and greater risk for conversion. Participants included 44 CHR participants and 32 healthy controls (CN) who completed the Effort Expenditure for Reward Task (EEfRT).

Compared to CN, CHR participants displayed reduced likelihood of exerting high effort for high probability and magnitude rewards. Among CHR participants, reduced effort expenditure was associated with greater negative symptom severity and greater probability of conversion to a psychotic disorder on a cross-sectional risk calculator.

Findings suggest that effort-cost computation is a marker of illness liability and a transphasic mechanism underlying negative symptoms in the SZ spectrum.

精神分裂症 (SZ) 之前通常有一个前驱期（即疾病前期），其特征是阳性症状减弱和功能结果下降。阴性症状在处于精神病临床高危 (CHR) 的个体（即具有前驱综合征的个体）中很突出，并且预示着会转化为疾病。CHR 人群中阴性症状的潜在机制尚不清楚。

当前的研究评估了 CHR 参与者是否表现出付出努力以获得奖励的意愿不足，以及这些损害是否与阴性症状和更大的转换风险相关。参与者包括 44 名 CHR 参与者和 32 名健康对照者 (CN)，他们完成了奖励任务 (EEfRT) 的努力支出。

与 CN 相比，CHR 参与者表现出为高概率和量级奖励付出高努力的可能性降低。在 CHR 参与者中，在横断面风险计算器上，减少的努力支出与更大的阴性症状严重程度和更大的转化为精神病的可能性相关。

研究结果表明，努力成本计算是疾病责任的标志，也是 SZ 谱中阴性症状潜在的跨相机制。