Division of Psychological Medicine, Institute of Psychiatry, King's College, London, UK.
Psychol Med. 2009 Dec;39(12):1943-55. doi: 10.1017/S0033291709990651. Epub 2009 Jul 23.
There is good evidence that psychotic symptoms segregate into symptom dimensions. However, it is still unclear how these dimensions are associated with risk indicators and other clinical variables, and whether they have advantages over categorical diagnosis in clinical practice. We investigated symptom dimensions in a first-onset psychosis sample and examined their associations with risk indicators and clinical variables. We then examined the relationship of categorical diagnoses to the same variables.
We recruited 536 patients as part of a population-based, incidence study of psychosis. Psychopathology was assessed using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN). A principal axis factor analysis was performed on symptom scores. The relationship of dimension scores with risk indicators and with clinical variables was then examined employing regression analyses. Finally, regression models were compared to assess the contribution of dimensions versus diagnosis in explaining these variables.
Factor analysis gave rise to a five-factor solution of manic, reality distortion, negative, depressive and disorganization symptom dimensions. The scores of identified dimensions were differentially associated with specific variables. The manic dimension had the highest number of significant associations; strong correlations were observed with shorter duration of untreated psychosis, acute mode of onset and compulsory admission. Adding dimensional scores to diagnostic categories significantly increased the amount of variability explained in predicting these variables; the reverse was also true but to a lesser extent.
Categorical and dimensional representations of psychosis are complementary. Using both appears to be a promising strategy in conceptualising psychotic illnesses.
有充分的证据表明，精神病症状可分为症状维度。然而，目前尚不清楚这些维度与风险指标和其他临床变量有何关联，以及它们在临床实践中是否优于分类诊断。我们在首发精神病患者样本中研究了症状维度，并检查了它们与风险指标和临床变量的关系。然后，我们检查了分类诊断与相同变量的关系。
我们招募了 536 名患者，作为精神病的基于人群、发病研究的一部分。使用神经精神病学临床评估计划（SCAN）评估精神病理学。对症状评分进行主成分因子分析。然后，使用回归分析检查维度评分与风险指标和临床变量的关系。最后，比较回归模型以评估维度与诊断在解释这些变量方面的贡献。
因子分析产生了一个五因素解决方案，包括躁狂、现实扭曲、负面、抑郁和紊乱症状维度。确定的维度得分与特定变量存在差异相关。躁狂维度有最多的显著关联；与未治疗精神病的持续时间较短、急性发病模式和强制入院呈强相关性。将维度评分添加到诊断类别中显著增加了预测这些变量的可变性解释；反之亦然，但程度较小。
精神病的分类和维度表示是互补的。同时使用这两种方法似乎是一种有前途的概念化精神病的策略。
