Study for Validation of Standardized Questionnaires on Depression and Investigation of the Frequency of Depression in Rheumatoid Arthritis (RA) Participants

The purpose of this study is to validate standardized questionnaires on depression for RA and to investigate the frequency of depression with RA. The study will include 2 parts, VADERA I and VADERA II. In VADERA I, 300 participants will be surveyed twice at an interval of 3 months regarding their current emotional condition using standardized questionnaires. On the basis of the results of VADERA I, in VADERA II, the selected questionnaire will be used to assess the prevalence of depression with RA in approximately 1000 participants.