Freeman Daniel, Emsley Richard, Dunn Graham, Fowler David, Bebbington Paul, Kuipers Elizabeth, Jolley Suzanne, Waller Helen, Hardy Amy, Garety Philippa
Department of Psychiatry, University of Oxford, Oxford, UK;
Centre for Biostatistics, Institute of Population Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK;
Schizophr Bull. 2015 Jul;41(4):971-9. doi: 10.1093/schbul/sbu173. Epub 2014 Dec 20.
For many patients with persecutory delusions, leaving home and going into crowded streets is a key clinical problem. In this study we aimed to inform treatment development by determining the psychological mechanisms whereby busy urban environments increase paranoia. In a randomized design with prespecified mediation analysis, we compared the effects on patients of going outside into a busy social environment with staying inside.
Fifty-nine patients with current persecutory delusions, in the context of nonaffective psychosis, reporting fears when going outside were assessed on factors from a cognitive model of paranoia. They were then randomized either to enter a busy local shopping street or to complete a neutral task indoors. They were then reassessed on the measures.
Compared with staying inside, the street exposure condition resulted in significant increases in paranoia, voices, anxiety, negative beliefs about the self, and negative beliefs about others. There was also a decrease in positive thoughts about the self. There was no alteration in reasoning processes. There were indications that the increase in paranoia was partially mediated by increases in anxiety (45%), depression (38%), and negative beliefs about others (45%).
We found that increases in negative affect may form an important route by which social exposure in urban environments triggers paranoid thoughts. The study provides an illustration of how an experimental approach can be applied to help understand a specific difficulty for patients with psychosis. In future studies the effects of specific elements of the social environment could be tested.
对于许多患有被害妄想症的患者而言，离开家前往拥挤的街道是一个关键的临床问题。在本研究中，我们旨在通过确定繁忙的城市环境增加偏执的心理机制来为治疗发展提供信息。在一项带有预先指定中介分析的随机设计中，我们比较了置身于繁忙社交环境中外出对患者的影响与待在室内的影响。
59名患有当前被害妄想症且处于非情感性精神病背景下、报告外出时有恐惧情绪的患者，依据偏执认知模型中的因素进行评估。然后，他们被随机分配到进入一条繁忙的当地商业街或在室内完成一项中性任务。之后，再次依据这些测量指标对他们进行评估。
与待在室内相比，街道暴露条件导致偏执、幻听、焦虑、对自我的消极信念以及对他人的消极信念显著增加。对自我的积极想法也有所减少。推理过程没有改变。有迹象表明，偏执的增加部分由焦虑增加（45%）、抑郁增加（38%）以及对他人的消极信念增加（45%）所介导。
我们发现消极情绪的增加可能构成城市环境中的社交暴露引发偏执想法的一条重要途径。该研究展示了如何运用实验方法来帮助理解精神病患者的一个特定难题。在未来的研究中，可以测试社会环境中特定元素的影响。
