Supplementary Material for: Who are people with psychosis delusional about? A study of social agents in the phenomenology of delusions

Introduction: Delusions frequently involve strong beliefs about, or interactions with, illusory social agents. Although such agents have been systematically described in hallucinations, few studies have investigated their nature and identity in delusions.

Methods: We identified 205 electronic mental health records describing the content of delusions from the Clinical Record Interactive Search (CRIS) platform at South London and Maudsley NHS Foundation Trust. Delusional content was classified as non-social, implicitly social, or explicitly social. Descriptions of illusory social agents from explicitly social delusions were extracted and categorized using an upward coding analysis. A hierarchical cluster analysis identified distinct groupings of illusory social agents.

Results: Most delusions (83.4%) contained explicit references to illusory social agents. Across 238 instances, we identified 220 distinct agent identities, with a mean of 1.17 agents per record. The majority were humans (85.1%), most often identified as family members (31.0%), followed by acquaintances (17.2%), religious figures (13.2%), unnamed persons (12.8%), professionals (11.8%), and cultural figures (10.9%). Hierarchical clustering revealed two distinct groups: one including socially proximate agents and the other more socially distant agents. These findings indicate a social gradient in delusions.

Conclusion: Social content predominates in delusions, with patients experiencing delusions about socially closer individuals more frequently. We discuss the extent to which social gradient may not be unique to delusional misidentification syndromes but may instead represent a general feature of delusions. Better characterization of social agents in delusions could inform mechanistic accounts of these symptoms and, in clinical practice, guide family support and risk assessment.

引言：妄想症常涉及对虚幻社交主体的坚定信念，或是与之产生互动。尽管此类主体在幻觉领域已得到系统性描述，但鲜有研究探讨其在妄想中的本质与身份属性。
方法：本研究从伦敦南部与莫兹利国民保健服务（NHS）基金会信托机构的临床记录交互搜索（Clinical Record Interactive Search, CRIS）平台中，筛选出205份记录妄想内容的电子心理健康档案。研究人员将妄想内容划分为非社交型、内隐社交型与外显社交型三类。针对外显社交型妄想中的虚幻社交主体描述，本研究采用上行编码分析法进行提取与归类，并通过层级聚类分析明确了虚幻社交主体的不同聚类组别。
结果：绝大多数妄想（83.4%）均明确提及虚幻社交主体。在238个样本案例中，本研究共识别出220种不同的主体身份，每份档案平均涉及1.17个主体。其中绝大多数主体为人类（85.1%），最常见的类别为家庭成员（31.0%），其次依次为熟人（17.2%）、宗教人物（13.2%）、未具名个体（12.8%）、专业人士（11.8%）与文化名人（10.9%）。层级聚类分析结果显示存在两个显著组别：一组为社交距离较近的主体，另一组为社交距离较远的主体。上述发现表明妄想存在社交梯度特征。
结论：社交内容在妄想中占据主导地位，患者更常出现针对社交距离较近个体的妄想症状。本研究探讨了社交梯度并非仅见于妄想性错认综合征，而可能是妄想的普遍特征这一命题的适用范围。更精准地刻画妄想中的社交主体特征，可为这类症状的机制研究提供理论支撑，同时在临床实践中可为家庭支持与风险评估工作提供指导。