Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London,London SE5 8AF,UK.
Department of Health Service and Population Research,Institute of Psychiatry, King's College London,De Crespigny Park, Denmark Hill, London SE5 8AF,UK.
Psychol Med. 2019 Jun;49(8):1378-1391. doi: 10.1017/S0033291718002131. Epub 2018 Oct 4.
The value of the nosological distinction between non-affective and affective psychosis has frequently been challenged. We aimed to investigate the transdiagnostic dimensional structure and associated characteristics of psychopathology at First Episode Psychosis (FEP). Regardless of diagnostic categories, we expected that positive symptoms occurred more frequently in ethnic minority groups and in more densely populated environments, and that negative symptoms were associated with indices of neurodevelopmental impairment.
This study included 2182 FEP individuals recruited across six countries, as part of the EUropean network of national schizophrenia networks studying Gene-Environment Interactions (EU-GEI) study. Symptom ratings were analysed using multidimensional item response modelling in Mplus to estimate five theory-based models of psychosis. We used multiple regression models to examine demographic and context factors associated with symptom dimensions.
A bifactor model, composed of one general factor and five specific dimensions of positive, negative, disorganization, manic and depressive symptoms, best-represented associations among ratings of psychotic symptoms. Positive symptoms were more common in ethnic minority groups. Urbanicity was associated with a higher score on the general factor. Men presented with more negative and less depressive symptoms than women. Early age-at-first-contact with psychiatric services was associated with higher scores on negative, disorganized, and manic symptom dimensions.
Our results suggest that the bifactor model of psychopathology holds across diagnostic categories of non-affective and affective psychosis at FEP, and demographic and context determinants map onto general and specific symptom dimensions. These findings have implications for tailoring symptom-specific treatments and inform research into the mood-psychosis spectrum.
非情感性和情感性精神病的分类价值经常受到质疑。我们旨在研究首次精神病发作（FEP）时精神病理学的跨诊断维度结构和相关特征。无论诊断类别如何，我们预计阳性症状在少数民族群体和人口更密集的环境中更为常见，而阴性症状与神经发育损伤的指标有关。
这项研究包括 2182 名来自六个国家的 FEP 个体，作为研究基因-环境相互作用的欧洲国家精神分裂症网络（EU-GEI）研究的一部分。使用 Mplus 中的多维项目反应建模分析症状评分，以估计五个基于理论的精神病模型。我们使用多元回归模型来检查与症状维度相关的人口统计学和环境因素。
一个由一个一般因素和五个阳性、阴性、紊乱、躁狂和抑郁症状的特定维度组成的双因素模型，最好地代表了精神病症状评分之间的关联。阳性症状在少数民族群体中更为常见。城市化程度与一般因素的得分较高有关。男性比女性表现出更多的阴性和更少的抑郁症状。与精神科服务的首次接触年龄较早与负面、紊乱和躁狂症状维度的得分较高有关。
我们的结果表明，双因素精神病模型在 FEP 的非情感性和情感性精神病的诊断类别中均成立，人口统计学和环境决定因素映射到一般和特定症状维度。这些发现对定制症状特异性治疗具有影响，并为研究情绪-精神病谱提供了信息。
