Code for: Expanding the positivity offset theory of anhedonia to the psychosis spectrum. In: Schizophrenia

Code for: Riehle, M., Pillny, M., & Lincoln, T. M. (2022). Expanding the positivity offset theory of anhedonia to the psychosis continuum. Schizophrenia, 8(1). https://doi.org/10.1038/s41537-022-00251-x Specifically, this is the code for the multilevel linear models used to assess differences between stimulus categories and for estimating Positivity Offset and Negativity Bias. People with schizophrenia and negative symptoms show diminished net positive emotion in low-arousing contexts (diminished positivity offset) and co-activate positive and negative emotion more frequently (increased ambivalence). Here, we investigated whether diminished positivity offset and increased ambivalence covary with negative symptoms along the continuum of psychotic symptoms. We conducted an online-study in an ad-hoc community sample (N = 261). Participants self-reported on psychotic symptoms (negative symptoms, depression, positive symptoms, anhedonia) and rated positivity, negativity, and arousal elicited by pleasant, unpleasant, and neutral stimuli. The data were analyzed with multilevel linear models. Increasing levels of all assessed symptom areas showed significant associations with diminished positivity offset. Increased ambivalence was related only to positive symptoms. Our results show that the diminished positivity offset is associated with psychotic symptoms in a community sample, including, but not limited to, negative symptoms. Ecological validity and symptom specificity require further investigation. Open Access funding enabled and organized by Projekt DEAL. unknown acceptedVersion

配套代码来源：Riehle M、Pillny M、Lincoln TM（2022）《将快感缺失（anhedonia）的阳性偏移（Positivity Offset）理论拓展至精神病连续体（psychosis continuum）》，发表于《精神分裂症（Schizophrenia）》第8卷第1期，DOI：https://doi.org/10.1038/s41537-022-00251-x。具体而言，本代码对应用于评估刺激类别间差异、并估算阳性偏移（Positivity Offset）与负性偏差（Negativity Bias）的多层线性模型（multilevel linear models）。存在精神分裂症及阴性症状（negative symptoms）的个体，在低唤醒情境下的净正性情绪水平受损（即阳性偏移减弱），且更频繁地同时激活正性与负性情绪（即矛盾情绪增强）。本研究旨在探究，在精神病连续体（psychosis continuum）中，阳性偏移减弱与矛盾情绪增强是否与阴性症状（negative symptoms）存在共变关系。研究采用在线实验范式，招募了特设社区样本（N=261）。参与者自行报告其精神病症状情况（涵盖阴性症状、抑郁症状、阳性症状（positive symptoms）及快感缺失），并对愉悦、不愉快与中性刺激所诱发的正性情绪、负性情绪及唤醒水平进行评分。研究采用多层线性模型对数据进行分析。所有评估的症状维度得分越高，与阳性偏移减弱均存在显著关联。而矛盾情绪增强仅与阳性症状（positive symptoms）存在显著关联。本研究结果表明，在社区样本中，阳性偏移减弱与精神病症状存在关联，且该关联不仅限于阴性症状。其生态效度与症状特异性仍需进一步研究验证。开放获取资助由Projekt DEAL发起并统筹。未知接受版本