Major depressive disorder (MDD) is conceptualized by individual symptoms occurring most of the day for at least two weeks. Despite this operationalization, MDD is highly variable with persons showing greater variation within and across days. Moreover, MDD is highly heterogeneous, varying considerably across people in both function and form. Recent efforts have examined MDD heterogeneity byinvestigating how symptoms influence one another over time across individuals in a system; however, these efforts have assumed that symptom dynamics are static and do not dynamically change over time. Nevertheless, it is possible that individual MDD system dynamics change continuously across time. Participants (N = 105) completed ratings of MDD symptoms three times a day for 90 days, and we conducted time varying vector autoregressive models to investigate the idiographic symptom networks. We then illustrated this finding with a case series of five persons with MDD. Supporting prior research, results indicate there is high heterogeneity across persons as individual network composition is unique from person to person. In addition, for most persons, individual symptom networks change dramatically across the 90 days, as evidenced by 86% of individuals experiencing at least one change in their most influential symptom and the median number of shifts being 3 over the 90 days. Additionally, most individuals had at least one symptom that acted as both the most and least influential symptom at any given point over the 90-day period. Our findings offer further insight into short-term symptom dynamics, suggesting that MDD is heterogeneous both across and within persons over time. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

中文翻译：

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抑郁症状作为一个异质且不断发展的动力系统：重度抑郁症患者症状快速变化的特有抑郁症状网络。


重度抑郁症 (MDD) 的概念是至少两周内每天大部分时间出现的个体症状。尽管有这种可操作性，MDD 仍然存在很大的差异，人们在几天内和不同天内表现出更大的变化。此外，MDD 具有高度异质性，不同人的功能和形式差异很大。最近的研究通过调查症状如何随着时间的推移在系统中的个体之间相互影响来检查 MDD 异质性。然而，这些努力假设症状动态是静态的，并且不会随时间动态变化。然而，单个 MDD 系统动态可能会随着时间的推移而不断变化。参与者 (N = 105) 在 90 天内每天完成 3 次 MDD 症状评级，我们进行了时变向量自回归模型来研究具体症状网络。然后，我们通过五个患有重度抑郁症的病例系列来说明这一发现。结果支持了先前的研究，表明人与人之间存在高度异质性，因为个体网络组成因人而异。此外，对于大多数人来说，个人症状网络在 90 天内发生了巨大变化，86% 的人在其最有影响力的症状中经历了至少一种变化，并且在 90 天内变化的中位数为 3 次，这证明了这一点。此外，大多数人至少有一种症状，在 90 天内的任何给定时间点上，该症状既是影响最大的症状，也是影响最小的症状。我们的研究结果进一步深入了解了短期症状动态，表明随着时间的推移，MDD 在人与人之间以及人与人之间都存在异质性。 （PsycInfo 数据库记录 (c) 2024 APA，保留所有权利）。