Delay discounting (DD) is the phenomenon of individuals discounting future rewards as a function of time. It has been studied extensively in chronic schizophrenia (SZ) and the results of these studies have been variable. Comorbidity in chronic samples could be one reason for the mixed findings and studies in first-episode (FE) samples are surprisingly lacking. Bipolar disorder (BP) which shares some genetic and symptom features with SZ could serve as an interesting comparison group for DD but has been underexplored. Here we present the first study that combines FE SZ, FE BP with psychotic features, as well as healthy controls and study DD with two versions of the task. We found that SZ showed steeper discounting than HC and BP on the well-validated Kirby DD task. SZ showed no difference than HC on a separate DD task with smaller rewards presented with decimal places and shorter delays. As a preliminary finding, DD was found to be positively related to positive symptoms in FE SZ, while no relationship was found between negative symptoms and DD. In addition, we found comparable DD in BP compared to HC. Ultimately, our data may help elucidate the psychopathology in SZ and BP during intertemporal decision making.

中文翻译：

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延迟折扣异常见于首发精神分裂症，但未见于双相情感障碍

延迟折扣 (DD) 是个人将未来奖励作为时间函数进行折扣的现象。它已在慢性精神分裂症 (SZ) 中得到广泛研究，这些研究的结果各不相同。慢性样本中的合并症可能是第一集 (FE) 样本中令人惊讶地缺乏混合发现和研究的一个原因。双相情感障碍 (BP) 与 SZ 具有一些遗传和症状特征，可以作为 DD 的一个有趣的比较组，但尚未得到充分探索。在这里，我们展示了第一项将 FE SZ、FE BP 与精神病特征以及健康对照和研究 DD 与两个版本的任务相结合的研究。我们发现 SZ 在经过充分验证的 Kirby DD 任务中显示出比 HC 和 BP 更大的折扣。在单独的 DD 任务中，SZ 与 HC 没有区别，较小的奖励以小数位和较短的延迟呈现。作为初步发现，发现 DD 与 FE SZ 中的阳性症状呈正相关，而阴性症状与 DD 之间没有关系。此外，我们发现与 HC 相比，BP 的 DD 具有可比性。最终，我们的数据可能有助于在跨期决策过程中阐明 SZ 和 BP 的精神病理学。