Bressan R A, Chaves A C, Shirakawa I, de Mari J
Department of Psychiatry, Federal University of São Paulo, Brazil.
Schizophr Res. 1998 Jun 22;32(1):41-9. doi: 10.1016/s0920-9964(98)00029-2.
Although depression is a well-established feature of schizophrenia, it is difficult to measure, because it overlaps with negative symptoms and extrapyramidal symptoms (EPS). Routinely adopted depression scales were not designed to be used in--cases of schizophrenia, and are known to perform poorly when trying to distinguish depression from other symptoms.
The aim of this study was to evaluate the validity of the Brazilian version of the Calgary Depression Rating Scale for Schizophrenia (CDSS).
Outpatients from four mental health units in the city of São Paulo, diagnosed as having schizophrenia by DSM-IV criteria, were evaluated by two independent raters who applied the DSM-IV depression criteria. All patients were assessed by means of the CDSS, the Positive and Negative Syndrome Scale (PANSS), and the Extrapyramidal Symptom Rating Scale (ESRS).
Eighty patients were recruited for the study. The analysis was carried out by comparing the DSM-IV criteria of depression with the CDSS scores, by means of the receiver operating characteristic (ROC) curves. The area under the ROC curve for major depression was 0.95 (SD = 0.02), and at a cut-off point of 6/7 the validity coefficients were as follows: sensibility 77%, specificity 92%, positive predictive value 67% and negative predictive value 95%. The area under the ROC curve for minor depression was 0.95 (SD = 0.02), and at a cut-off point of 4/5 the validity coefficients were as follows: sensibility 95%, specificity 88%, positive predictive value 75% and negative predictive value 98%. The correlation coefficients between the CDSS scores, the PANSS negative and positive subscale scores, and the ESRS scores were all below 0.50.
It can be concluded that the Brazilian version of the CDSS is a valid research tool to assess depressive episodes for stabilized patients with schizophrenia.
尽管抑郁是精神分裂症的一个公认特征，但由于它与阴性症状和锥体外系症状（EPS）重叠，所以很难测量。常规采用的抑郁量表并非为精神分裂症患者设计，且已知在试图区分抑郁与其他症状时表现不佳。
本研究旨在评估巴西版精神分裂症卡尔加里抑郁评定量表（CDSS）的有效性。
来自圣保罗市四个精神卫生单位、根据DSM-IV标准诊断为精神分裂症的门诊患者，由两名独立评估者依据DSM-IV抑郁标准进行评估。所有患者均通过CDSS、阳性和阴性症状量表（PANSS）以及锥体外系症状评定量表（ESRS）进行评估。
80名患者被纳入本研究。通过绘制受试者工作特征（ROC）曲线，将抑郁的DSM-IV标准与CDSS评分进行比较来开展分析。重度抑郁的ROC曲线下面积为0.95（标准差=0.02），在临界值为6/7时，效度系数如下：敏感性77%，特异性92%，阳性预测值67%，阴性预测值95%。轻度抑郁的ROC曲线下面积为0.95（标准差=0.02），在临界值为4/5时，效度系数如下：敏感性95%，特异性88%，阳性预测值75%，阴性预测值98%。CDSS评分、PANSS阴性和阳性分量表评分以及ESRS评分之间的相关系数均低于0.50。
可以得出结论，巴西版CDSS是评估稳定期精神分裂症患者抑郁发作的有效研究工具。
