Möller H J, Müller H
Psychiatric Hospital, Ludwig Maximilian University Munich, Germany.
Eur Arch Psychiatry Clin Neurosci. 1997;247(1):1-5. doi: 10.1007/BF02916246.
The differentiation between primary and secondary negative symptoms in schizophrenia (Carpenter et al. 1985) is an important issue. Path analysis allows to estimate statistically whether, and in which degree, the effect of a neuroleptic on negative symptoms is mediated by effects on positive, extrapyramidal, and depressive symptoms (Möller et al. 1995). If certain causal relationships are theoretically assumed-as proposed by Carpenter et al. (1985)-then path analysis can be applied to estimate the quantitative degree of these relationships, although the causal directions cannot be inferred from path analysis itself. Especially it can be estimated whether there is sufficient evidence for a "direct effect" of neuroleptic treatment on (primary) negative symptoms, an effect which is not mediated by positive, extrapyramidal, and/or depressive symptoms. We show the correspondence between the applied path model and several simple regression equations which can be estimated with standard statistical software. Moreover, we report some Monte Carlo studies showing that the results reported by Möller et al. (1995)-a "direct effect" of risperidone (6 mg) on negative symptoms compared with haloperidol (20 mg)-cannot be explained by a path model in which, everything else being equal, positive symptoms depend on negative symptoms instead of the other way around.
精神分裂症中原发性与继发性阴性症状的区分（Carpenter等人，1985年）是一个重要问题。路径分析能够从统计学上估计抗精神病药物对阴性症状的影响是否以及在何种程度上由对阳性、锥体外系和抑郁症状的影响所介导（Möller等人，1995年）。如果像Carpenter等人（1985年）所提出的那样在理论上假定某些因果关系，那么尽管无法从路径分析本身推断出因果方向，但仍可应用路径分析来估计这些关系的定量程度。尤其可以估计抗精神病药物治疗对（原发性）阴性症状的“直接效应”是否有充分证据，这种效应并非由阳性、锥体外系和/或抑郁症状所介导。我们展示了所应用的路径模型与几个可用标准统计软件估计的简单回归方程之间的对应关系。此外，我们报告了一些蒙特卡罗研究，结果表明Möller等人（1995年）所报告的结果——与氟哌啶醇（20毫克）相比，利培酮（6毫克）对阴性症状有“直接效应”——无法用一个路径模型来解释，在该模型中，在其他条件相同的情况下，阳性症状取决于阴性症状而非相反。
