The Japanese version of the Depressive Experiences Questionnaire: its reliability and validity for lifetime depression in a working population.

We have developed a Japanese version of the Depressive Experiences Questionnaire (DEQ), devised by Blatt et al., for assessing depression-prone personality and examined the questionnaire's reliability (test-retest reliability and internal consistency) and validity. To examine the questionnaire's validity, we evaluated its factorial validity and discriminant power for depression (i.e., construct validity). To test the construct validity of the DEQ with and without depression proneness, the scores on the DEQ subscales were compared between subjects with and without a lifetime history of major depressive disorder (MDD). The Inventory to Diagnose Depression, Lifetime version (IDDL), was used to identify lifetime depression. The reliability tests showed that the Japanese version has reliability almost similar to that of the original version. While the self-criticism has good reliability, the dependency appears to have only modest reliability. In the comparisons between subjects with and without lifetime histories of major depression, the former had significantly higher scores on the self-criticism dimension of the DEQ than did the latter, suggesting that the Japanese version of the DEQ, especially the self-criticism, may have the ability to distinguish individuals with lifetime depression from normal controls. We conclude that the DEQ is an acceptable instrument for assessing the depression-prone personality.