Boyer P, Lecrubier Y, Rein W
INSERM, CMME, Paris.
Encephale. 1996 Jun;22 Spec No 2:25-7.
Several types of limitations are inherent in the evaluation of changes in negative symptoms during clinical trials. Some of these limitations can be listed as follows: the need to select homogeneous study populations (use of a standardized diagnosis), identification of negative dimensions which feature deficitary forms of schizophrenia (qualitative criteria and threshold scores using negative symptom rating tables), strict control of variables which may induce secondary negative symptoms (treatments, other associated disorders particularly of a depressive type, lack of environmental stimulus), follow-up of stability of negative symptoms and, finally, an adequate time interval for evaluation in order to exclude spontaneous and non-specific fluctuations of symptomatology.
在临床试验中评估阴性症状变化时，存在几种固有的局限性。其中一些局限性可列举如下：需要选择同质的研究人群（使用标准化诊断）；识别以精神分裂症缺陷形式为特征的阴性维度（使用阴性症状评定表的定性标准和阈值分数）；严格控制可能诱发继发性阴性症状的变量（治疗、其他相关疾病，尤其是抑郁类型、缺乏环境刺激）；跟踪阴性症状的稳定性，最后，要有足够的评估时间间隔，以排除症状的自发和非特异性波动。
