Depression is improved when low-dose tacrolimus is given to rheumatoid arthritis patients showing an inadequate response to biologic agents

PURPOSE: Depression in rheumatoid arthritis (RA) patients is more severe than in healthy people. Herein, we report improved depression in RA patients using biologic agents. We examined whether depression was improved by tacrolimus combination therapy when biologic agents were ineffective. METHOD: The study included 13 RA patients who used biologic agents. The following methods were used before the initiation of tacrolimus combination therapy and at 14 and 30 weeks after treatment initiation: the Zung self-rating depression scale (SDS) to evaluate depression state, disease activity score 28/erythrocyte sedimentation rate (DAS28), tender joint counts, swollen joint counts, a patient global assessment to evaluate RA disease activity, and the modified health assessment questionnaire (mHAQ) to evaluate quality of life. RESULTS: The SDS scores before the initiation of tacrolimus combination therapy and at 14 and 30 weeks after treatment initiation were 45.2 ± 10.6, 44.8 ± 12.8, and 41.6 ± 11.2 (p = 0.047), respectively, indicating significant improvement. The DAS28 was 5.0 ± 1.3 prior to treatment, 3.8 ± 1.3 at 14 weeks, and 3.5 ± 0.9 at 30 weeks, demonstrating significant improvement at both 14 and 30 weeks (p < 0.001). The mHAQ score changed from 0.60 ± 0.45 at baseline to 0.54 ± 0.52 and 0.38 ± 0.43 at 14 and 30 weeks, respectively. The mHAQ score was significantly lower at 30 weeks when compared to baseline (p = 0.013). CONCLUSION: Tacrolimus combination therapy does not directly improve depression in RA patients, but it is possible that the observed improvement in depression accompanies the improvement in the secondary failure of RA.