[Psychiatric symptom dimensions induced by work stress--an application of redundancy analysis]

The relationship between work stress estimated by a work stress questionnaire and several psychic symptoms estimated by a psychiatric symptom questionnaire was examined by redundancy analysis, which is a multivariate statistical technique to determine two sets of variables, one set being dependent on the other. Its aim is maximization of the explained variance of the dependent variables by the linear combination of the explanatory variables. The results showed that the depressive items had the largest loadings on the work stress variables, when the psychiatric symptom questionnaire was used as dependent variable and that the dullness dimension and the concentration difficulty dimension tended to have high loadings, when the same analysis was done using the subjective fatigue feeling questionnaire and the work stress questionnaire. We ascertained that these two fatigue symptom dimensions, especially the latter, are identical with the depression dimension in the psychiatric questionnaire. We concluded that work stress might induce a depressive state rather than other psychological or psychiatric states.