Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands.
Psychol Med. 2012 May;42(5):957-65. doi: 10.1017/S003329171100211X. Epub 2011 Nov 18.
Previous research has shown that stressful life events (SLEs) influence the pattern of individual depressive symptoms. However, we do not know how these differences arise. Two theories about the nature of psychiatric disorders have different predictions about the source of these differences: (1) SLEs influence depressive symptoms and correlations between them indirectly, via an underlying acute liability to develop a dysphoric episode (DE; common cause hypothesis); and (2) SLEs influence depressive symptoms and correlations between them directly (network hypothesis). The present study investigates the predictions of these two theories.
We divided a population-based sample of 2096 Caucasian twins (49.9% female) who reported at least two aggregated depressive symptoms in the last year into four groups, based on the SLE they reported causing their symptoms. For these groups, we calculated tetrachoric correlations between the 14 disaggregated depressive symptoms and, subsequently, tested whether the resulting correlation patterns were significantly different and if those differences could be explained by underlying differences in a single acute liability to develop a DE.
The four SLE groups had markedly different correlation patterns between the depressive symptoms. These differences were significant and could not be explained by underlying differences in the acute liability to develop a DE.
Our results are not compatible with the common cause perspective but are consistent with the predictions of the network hypothesis. We elaborate on the implications of a conceptual shift to the network perspective for our diagnostic and philosophical approach to the concept of what constitutes a psychiatric disorder.
先前的研究表明，生活应激事件（SLE）会影响个体抑郁症状的模式。然而，我们不知道这些差异是如何产生的。关于精神障碍性质的两种理论对这些差异的来源有不同的预测：（1）SLE 通过潜在的易发性来间接影响抑郁症状和它们之间的相关性，从而引发抑郁发作（DE；共同原因假设）；（2）SLE 直接影响抑郁症状和它们之间的相关性（网络假设）。本研究调查了这两种理论的预测。
我们根据报告导致症状的 SLE 将一个基于人群的 2096 对白种人双胞胎（49.9%为女性）样本（过去一年至少报告两次聚合性抑郁症状）分为四组。对于这些组，我们计算了 14 种离散抑郁症状之间的 tetrachoric 相关系数，随后测试了由此产生的相关模式是否显著不同，以及这些差异是否可以用 DE 发展的单一急性易发性的潜在差异来解释。
四个 SLE 组之间的抑郁症状的相关模式有明显差异。这些差异是显著的，不能用 DE 发展的急性易发性的潜在差异来解释。
我们的结果与共同原因观点不一致，但与网络假设的预测一致。我们详细阐述了概念从共同原因观点向网络观点转变对我们的诊断和哲学方法的影响，即构成精神障碍的概念。
