CAN POSITIVE AFFECT ITEMS BE USED TO ASSESS DEPRESSIVE-DISORDERS IN THE JAPANESE POPULATION

Background. The purpose of the present study was to examine the measur ement properties of positive affect items among the Japanese populatio n. Methods. Responses to the Japanese version of the Center for Epidem iologic Studies Depression Scale and four additional negatively revise d items of the original positive affect items were compared for 85 Jap anese psychiatric out-patients with dysphoric-mood-related symptoms an d 255 demographically matched controls. Results. Responses to positive affect items were generally comparable between the two groups, wherea s responses to negative symptom items were markedly different (P < 0.0 02 for all comparisons). The group difference was most marked for symp tom persistence. Responses to the four negatively revised items of pos itive affect revealed a similar picture to that of the negative sympto m items. The internal consistency of the scale significantly improved when the original positive affect items were replaced by the negativel y revised items (P < 0.001 for both). Conclusions. Positive affect ite ms with positive wording cannot be used to assess depressive disorders in the Japanese population adequately, but this can be done with the corresponding negatively revised items.