Kiloh L G, Garside R F
Aust N Z J Psychiatry. 1977 Sep;11(3):149-56. doi: 10.3109/00048677709159553.
Principal component analyses were carried out on 51 items abstracted from Lewis's 1934 and 1936 papers. The first component was bipolar, differentiating between endogenous items and those that were mainly neurotic. The distributions of the first component scores by cluster indicated that there were two separate clusters of patients, one mainly endogenous, the other neurotic. It was concluded that Lewis's data indicate that there are at least two qualitatively different depressive illnesses. Further component analyses were carried out using the 25 endogenous items. The first component was a general one of endogenous depression. The distributions of its scores were bimodal, indicating that there were two groups of patients, those who suffered from endogenous depression and those who did not. These analyses indicated that endogenous depression is a categorical illness.
对从刘易斯1934年和1936年论文中提取的51个项目进行了主成分分析。第一个成分是两极的，区分内源性项目和主要是神经症性的项目。按聚类分析的第一个成分得分分布表明，有两组不同的患者，一组主要是内源性的，另一组是神经症性的。得出的结论是，刘易斯的数据表明至少有两种性质不同的抑郁症。使用25个内源性项目进行了进一步的成分分析。第一个成分是内源性抑郁的一个一般性成分。其得分分布是双峰的，表明有两组患者，一组患有内源性抑郁症，另一组没有。这些分析表明内源性抑郁症是一种分类性疾病。
